diff --git a/.gradle/4.10.3/fileChanges/last-build.bin b/.gradle/4.10.3/fileChanges/last-build.bin
new file mode 100644
index 0000000..f76dd23
Binary files /dev/null and b/.gradle/4.10.3/fileChanges/last-build.bin differ
diff --git a/.gradle/4.10.3/fileHashes/fileHashes.bin b/.gradle/4.10.3/fileHashes/fileHashes.bin
new file mode 100644
index 0000000..6def6cf
Binary files /dev/null and b/.gradle/4.10.3/fileHashes/fileHashes.bin differ
diff --git a/.gradle/4.10.3/fileHashes/fileHashes.lock b/.gradle/4.10.3/fileHashes/fileHashes.lock
new file mode 100644
index 0000000..b634259
Binary files /dev/null and b/.gradle/4.10.3/fileHashes/fileHashes.lock differ
diff --git a/.gradle/4.10.3/gc.properties b/.gradle/4.10.3/gc.properties
new file mode 100644
index 0000000..e69de29
diff --git a/.gradle/4.10.3/taskHistory/taskHistory.bin b/.gradle/4.10.3/taskHistory/taskHistory.bin
new file mode 100644
index 0000000..3039775
Binary files /dev/null and b/.gradle/4.10.3/taskHistory/taskHistory.bin differ
diff --git a/.gradle/4.10.3/taskHistory/taskHistory.lock b/.gradle/4.10.3/taskHistory/taskHistory.lock
new file mode 100644
index 0000000..67c43ec
Binary files /dev/null and b/.gradle/4.10.3/taskHistory/taskHistory.lock differ
diff --git a/.gradle/6.7.1/executionHistory/executionHistory.bin b/.gradle/6.7.1/executionHistory/executionHistory.bin
new file mode 100644
index 0000000..ac8f0f1
Binary files /dev/null and b/.gradle/6.7.1/executionHistory/executionHistory.bin differ
diff --git a/.gradle/6.7.1/executionHistory/executionHistory.lock b/.gradle/6.7.1/executionHistory/executionHistory.lock
new file mode 100644
index 0000000..a2fcdd6
Binary files /dev/null and b/.gradle/6.7.1/executionHistory/executionHistory.lock differ
diff --git a/.gradle/6.7.1/fileChanges/last-build.bin b/.gradle/6.7.1/fileChanges/last-build.bin
new file mode 100644
index 0000000..f76dd23
Binary files /dev/null and b/.gradle/6.7.1/fileChanges/last-build.bin differ
diff --git a/.gradle/6.7.1/fileHashes/fileHashes.bin b/.gradle/6.7.1/fileHashes/fileHashes.bin
new file mode 100644
index 0000000..37531ae
Binary files /dev/null and b/.gradle/6.7.1/fileHashes/fileHashes.bin differ
diff --git a/.gradle/6.7.1/fileHashes/fileHashes.lock b/.gradle/6.7.1/fileHashes/fileHashes.lock
new file mode 100644
index 0000000..c8cff16
Binary files /dev/null and b/.gradle/6.7.1/fileHashes/fileHashes.lock differ
diff --git a/.gradle/6.7.1/gc.properties b/.gradle/6.7.1/gc.properties
new file mode 100644
index 0000000..e69de29
diff --git a/.gradle/6.7.1/javaCompile/classAnalysis.bin b/.gradle/6.7.1/javaCompile/classAnalysis.bin
new file mode 100644
index 0000000..4876ce4
Binary files /dev/null and b/.gradle/6.7.1/javaCompile/classAnalysis.bin differ
diff --git a/.gradle/6.7.1/javaCompile/javaCompile.lock b/.gradle/6.7.1/javaCompile/javaCompile.lock
new file mode 100644
index 0000000..bc3ec7b
Binary files /dev/null and b/.gradle/6.7.1/javaCompile/javaCompile.lock differ
diff --git a/.gradle/6.7.1/javaCompile/taskHistory.bin b/.gradle/6.7.1/javaCompile/taskHistory.bin
new file mode 100644
index 0000000..a7fcb8d
Binary files /dev/null and b/.gradle/6.7.1/javaCompile/taskHistory.bin differ
diff --git a/.gradle/buildOutputCleanup/buildOutputCleanup.lock b/.gradle/buildOutputCleanup/buildOutputCleanup.lock
new file mode 100644
index 0000000..53d9390
Binary files /dev/null and b/.gradle/buildOutputCleanup/buildOutputCleanup.lock differ
diff --git a/.gradle/buildOutputCleanup/cache.properties b/.gradle/buildOutputCleanup/cache.properties
new file mode 100644
index 0000000..e0a5c88
--- /dev/null
+++ b/.gradle/buildOutputCleanup/cache.properties
@@ -0,0 +1,2 @@
+#Wed Nov 18 16:09:32 EAT 2020
+gradle.version=6.7.1
diff --git a/.gradle/buildOutputCleanup/outputFiles.bin b/.gradle/buildOutputCleanup/outputFiles.bin
new file mode 100644
index 0000000..981b69f
Binary files /dev/null and b/.gradle/buildOutputCleanup/outputFiles.bin differ
diff --git a/.gradle/checksums/checksums.lock b/.gradle/checksums/checksums.lock
new file mode 100644
index 0000000..6cb49be
Binary files /dev/null and b/.gradle/checksums/checksums.lock differ
diff --git a/.gradle/configuration-cache/gc.properties b/.gradle/configuration-cache/gc.properties
new file mode 100644
index 0000000..e69de29
diff --git a/.gradle/vcs-1/gc.properties b/.gradle/vcs-1/gc.properties
new file mode 100644
index 0000000..e69de29
diff --git a/.idea/gradle.xml b/.idea/gradle.xml
index e6fe19b..e1ca92e 100644
--- a/.idea/gradle.xml
+++ b/.idea/gradle.xml
@@ -1,9 +1,12 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
+  <component name="GradleMigrationSettings" migrationVersion="1" />
   <component name="GradleSettings">
     <option name="linkedExternalProjectsSettings">
       <GradleProjectSettings>
         <option name="createEmptyContentRootDirectories" value="true" />
+        <option name="delegatedBuild" value="false" />
+        <option name="testRunner" value="PLATFORM" />
         <option name="distributionType" value="WRAPPED" />
         <option name="externalProjectPath" value="$PROJECT_DIR$" />
         <option name="modules">
diff --git a/.idea/workspace.xml b/.idea/workspace.xml
index 41278b9..1454b07 100644
--- a/.idea/workspace.xml
+++ b/.idea/workspace.xml
@@ -2,67 +2,24 @@
 <project version="4">
   <component name="ChangeListManager">
     <list default="true" id="2fe51d8c-7a26-4d1d-a5ec-e91ad80e600f" name="Default Changelist" comment="">
-      <change afterPath="$PROJECT_DIR$/.idea/vcs.xml" afterDir="false" />
-      <change afterPath="$PROJECT_DIR$/src/test/java/models/PingPongTest.java" afterDir="false" />
+      <change afterPath="$PROJECT_DIR$/src/test/java/AppTest.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/.idea/gradle.xml" beforeDir="false" afterPath="$PROJECT_DIR$/.idea/gradle.xml" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/.idea/workspace.xml" beforeDir="false" afterPath="$PROJECT_DIR$/.idea/workspace.xml" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/main/java/App.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/main/java/App.java" afterDir="false" />
       <change beforePath="$PROJECT_DIR$/src/main/java/models/PingPong.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/main/java/models/PingPong.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/test/java/models/PingPongTest.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/test/java/models/PingPongTest.java" afterDir="false" />
     </list>
-    <ignored path="$PROJECT_DIR$/classes/" />
-    <ignored path="$PROJECT_DIR$/.gradle/" />
-    <ignored path="$PROJECT_DIR$/build/" />
-    <ignored path="$PROJECT_DIR$/out/" />
     <option name="EXCLUDED_CONVERTED_TO_IGNORED" value="true" />
     <option name="SHOW_DIALOG" value="false" />
     <option name="HIGHLIGHT_CONFLICTS" value="true" />
     <option name="HIGHLIGHT_NON_ACTIVE_CHANGELIST" value="false" />
     <option name="LAST_RESOLUTION" value="IGNORE" />
   </component>
-  <component name="DefaultGradleProjectSettings">
-    <option name="isMigrated" value="true" />
-  </component>
   <component name="ExternalProjectsData">
     <projectState path="$PROJECT_DIR$">
       <ProjectState />
     </projectState>
   </component>
-  <component name="FileEditorManager">
-    <leaf>
-      <file pinned="false" current-in-tab="false">
-        <entry file="file://$PROJECT_DIR$/src/main/java/App.java">
-          <provider selected="true" editor-type-id="text-editor">
-            <state relative-caret-position="15">
-              <caret line="1" lean-forward="true" selection-start-line="1" selection-end-line="1" />
-            </state>
-          </provider>
-        </entry>
-      </file>
-      <file pinned="false" current-in-tab="true">
-        <entry file="file://$PROJECT_DIR$/src/main/java/models/PingPong.java">
-          <provider selected="true" editor-type-id="text-editor">
-            <state relative-caret-position="135">
-              <caret line="9" column="20" selection-start-line="9" selection-start-column="20" selection-end-line="9" selection-end-column="20" />
-              <folding>
-                <element signature="imports" expanded="true" />
-                <element signature="e#199#207#0" expanded="true" />
-              </folding>
-            </state>
-          </provider>
-        </entry>
-      </file>
-      <file pinned="false" current-in-tab="false">
-        <entry file="file://$PROJECT_DIR$/src/test/java/models/PingPongTest.java">
-          <provider selected="true" editor-type-id="text-editor">
-            <state relative-caret-position="210">
-              <caret line="14" column="5" selection-start-line="14" selection-start-column="5" selection-end-line="14" selection-end-column="5" />
-              <folding>
-                <element signature="imports" expanded="true" />
-                <element signature="e#315#323#0" expanded="true" />
-              </folding>
-            </state>
-          </provider>
-        </entry>
-      </file>
-    </leaf>
-  </component>
   <component name="FileTemplateManagerImpl">
     <option name="RECENT_TEMPLATES">
       <list>
@@ -73,76 +30,18 @@
   <component name="Git.Settings">
     <option name="RECENT_GIT_ROOT_PATH" value="$PROJECT_DIR$" />
   </component>
-  <component name="IdeDocumentHistory">
-    <option name="CHANGED_PATHS">
-      <list>
-        <option value="$PROJECT_DIR$/src/test/java/models/PingPongTest.java" />
-        <option value="$PROJECT_DIR$/src/main/java/models/PingPong.java" />
-      </list>
-    </option>
-  </component>
-  <component name="ProjectFrameBounds">
-    <option name="x" value="10" />
-    <option name="y" value="20" />
-    <option name="width" value="1346" />
-    <option name="height" value="728" />
-  </component>
+  <component name="ProjectId" id="1kSMViJzaqXb6klfG9C4kgcsf6o" />
   <component name="ProjectLevelVcsManager" settingsEditedManually="true" />
-  <component name="ProjectView">
-    <navigator proportions="" version="1">
-      <foldersAlwaysOnTop value="true" />
-    </navigator>
-    <panes>
-      <pane id="ProjectPane">
-        <subPane>
-          <expand>
-            <path>
-              <item name="Java-Ping-Pong-StarterCode-master" type="b2602c69:ProjectViewProjectNode" />
-              <item name="Java-Ping-Pong-StarterCode-master" type="8a07ba80:GradleTreeStructureProvider$GradleModuleDirectoryNode" />
-            </path>
-            <path>
-              <item name="Java-Ping-Pong-StarterCode-master" type="b2602c69:ProjectViewProjectNode" />
-              <item name="Java-Ping-Pong-StarterCode-master" type="8a07ba80:GradleTreeStructureProvider$GradleModuleDirectoryNode" />
-              <item name="src" type="462c0819:PsiDirectoryNode" />
-            </path>
-            <path>
-              <item name="Java-Ping-Pong-StarterCode-master" type="b2602c69:ProjectViewProjectNode" />
-              <item name="Java-Ping-Pong-StarterCode-master" type="8a07ba80:GradleTreeStructureProvider$GradleModuleDirectoryNode" />
-              <item name="src" type="462c0819:PsiDirectoryNode" />
-              <item name="main" type="8a07ba80:GradleTreeStructureProvider$GradleModuleDirectoryNode" />
-            </path>
-            <path>
-              <item name="Java-Ping-Pong-StarterCode-master" type="b2602c69:ProjectViewProjectNode" />
-              <item name="Java-Ping-Pong-StarterCode-master" type="8a07ba80:GradleTreeStructureProvider$GradleModuleDirectoryNode" />
-              <item name="src" type="462c0819:PsiDirectoryNode" />
-              <item name="main" type="8a07ba80:GradleTreeStructureProvider$GradleModuleDirectoryNode" />
-              <item name="java" type="462c0819:PsiDirectoryNode" />
-            </path>
-            <path>
-              <item name="Java-Ping-Pong-StarterCode-master" type="b2602c69:ProjectViewProjectNode" />
-              <item name="Java-Ping-Pong-StarterCode-master" type="8a07ba80:GradleTreeStructureProvider$GradleModuleDirectoryNode" />
-              <item name="src" type="462c0819:PsiDirectoryNode" />
-              <item name="main" type="8a07ba80:GradleTreeStructureProvider$GradleModuleDirectoryNode" />
-              <item name="java" type="462c0819:PsiDirectoryNode" />
-              <item name="models" type="462c0819:PsiDirectoryNode" />
-            </path>
-          </expand>
-          <select />
-        </subPane>
-      </pane>
-      <pane id="PackagesPane" />
-      <pane id="Scope" />
-    </panes>
-  </component>
   <component name="PropertiesComponent">
     <property name="SHARE_PROJECT_CONFIGURATION_FILES" value="true" />
     <property name="com.intellij.testIntegration.createTest.CreateTestDialog.defaultLibrary" value="JUnit4" />
     <property name="com.intellij.testIntegration.createTest.CreateTestDialog.defaultLibrarySuperClass.JUnit4" value="" />
     <property name="last_opened_file_path" value="$PROJECT_DIR$" />
-    <property name="settings.editor.selected.configurable" value="editor.preferences.appearance" />
+    <property name="settings.editor.selected.configurable" value="reference.settingsdialog.project.gradle" />
   </component>
   <component name="RecentsManager">
     <key name="CreateTestDialog.RecentsKey">
+      <recent name="" />
       <recent name="models" />
     </key>
     <key name="CreateTestDialog.Recents.Supers">
@@ -161,6 +60,28 @@
       </list>
     </option>
   </component>
+  <component name="RunManager">
+    <configuration name="PingPongTest" type="JUnit" factoryName="JUnit" temporary="true" nameIsGenerated="true">
+      <module name="Java_Ping_Pong_StarterCode.test" />
+      <extension name="coverage">
+        <pattern>
+          <option name="PATTERN" value="models.*" />
+          <option name="ENABLED" value="true" />
+        </pattern>
+      </extension>
+      <option name="PACKAGE_NAME" value="models" />
+      <option name="MAIN_CLASS_NAME" value="models.PingPongTest" />
+      <option name="TEST_OBJECT" value="class" />
+      <method v="2">
+        <option name="Make" enabled="true" />
+      </method>
+    </configuration>
+    <recent_temporary>
+      <list>
+        <item itemvalue="JUnit.PingPongTest" />
+      </list>
+    </recent_temporary>
+  </component>
   <component name="SvnConfiguration">
     <configuration />
   </component>
@@ -174,69 +95,18 @@
     </task>
     <servers />
   </component>
-  <component name="ToolWindowManager">
-    <frame x="10" y="20" width="1346" height="728" extended-state="0" />
-    <editor active="true" />
-    <layout>
-      <window_info active="true" content_ui="combo" id="Project" order="0" visible="true" weight="0.25383437" />
-      <window_info id="Structure" order="1" side_tool="true" weight="0.25" />
-      <window_info id="Image Layers" order="2" />
-      <window_info id="Designer" order="3" />
-      <window_info id="Capture Tool" order="4" />
-      <window_info id="UI Designer" order="5" />
-      <window_info id="Favorites" order="6" side_tool="true" />
-      <window_info anchor="bottom" id="Message" order="0" />
-      <window_info anchor="bottom" id="Find" order="1" />
-      <window_info anchor="bottom" id="Run" order="2" />
-      <window_info anchor="bottom" id="Debug" order="3" weight="0.4" />
-      <window_info anchor="bottom" id="Cvs" order="4" weight="0.25" />
-      <window_info anchor="bottom" id="Inspection" order="5" weight="0.4" />
-      <window_info anchor="bottom" id="TODO" order="6" />
-      <window_info anchor="bottom" id="Terminal" order="7" visible="true" weight="0.3289689" />
-      <window_info anchor="bottom" id="Event Log" order="8" side_tool="true" />
-      <window_info anchor="bottom" id="Version Control" order="9" />
-      <window_info anchor="bottom" id="Build" order="10" visible="true" weight="0.3289689" />
-      <window_info anchor="right" id="Commander" internal_type="SLIDING" order="0" type="SLIDING" weight="0.4" />
-      <window_info anchor="right" id="Ant Build" order="1" weight="0.25" />
-      <window_info anchor="right" content_ui="combo" id="Hierarchy" order="2" weight="0.25" />
-      <window_info anchor="right" id="Palette" order="3" />
-      <window_info anchor="right" id="Maven" order="4" />
-      <window_info anchor="right" id="Gradle" order="5" />
-      <window_info anchor="right" id="Theme Preview" order="6" />
-      <window_info anchor="right" id="Capture Analysis" order="7" />
-      <window_info anchor="right" id="Palette&#9;" order="8" />
-    </layout>
-  </component>
-  <component name="editorHistoryManager">
-    <entry file="file://$PROJECT_DIR$/src/main/java/App.java">
-      <provider selected="true" editor-type-id="text-editor">
-        <state relative-caret-position="15">
-          <caret line="1" lean-forward="true" selection-start-line="1" selection-end-line="1" />
-        </state>
-      </provider>
-    </entry>
-    <entry file="file://$PROJECT_DIR$/src/test/java/models/PingPongTest.java">
-      <provider selected="true" editor-type-id="text-editor">
-        <state relative-caret-position="210">
-          <caret line="14" column="5" selection-start-line="14" selection-start-column="5" selection-end-line="14" selection-end-column="5" />
-          <folding>
-            <element signature="imports" expanded="true" />
-            <element signature="e#315#323#0" expanded="true" />
-          </folding>
-        </state>
-      </provider>
-    </entry>
-    <entry file="file://$PROJECT_DIR$/src/main/java/models/PingPong.java">
-      <provider selected="true" editor-type-id="text-editor">
-        <state relative-caret-position="135">
-          <caret line="9" column="20" selection-start-line="9" selection-start-column="20" selection-end-line="9" selection-end-column="20" />
-          <folding>
-            <element signature="imports" expanded="true" />
-            <element signature="e#199#207#0" expanded="true" />
-          </folding>
-        </state>
-      </provider>
-    </entry>
+  <component name="Vcs.Log.Tabs.Properties">
+    <option name="TAB_STATES">
+      <map>
+        <entry key="MAIN">
+          <value>
+            <State>
+              <option name="COLUMN_ORDER" />
+            </State>
+          </value>
+        </entry>
+      </map>
+    </option>
   </component>
   <component name="masterDetails">
     <states>
diff --git a/build/classes/java/main/App.class b/build/classes/java/main/App.class
new file mode 100644
index 0000000..ffd36d9
Binary files /dev/null and b/build/classes/java/main/App.class differ
diff --git a/build/classes/java/main/models/PingPong.class b/build/classes/java/main/models/PingPong.class
new file mode 100644
index 0000000..4dd243f
Binary files /dev/null and b/build/classes/java/main/models/PingPong.class differ
diff --git a/build/tmp/compileJava/source-classes-mapping.txt b/build/tmp/compileJava/source-classes-mapping.txt
new file mode 100644
index 0000000..066859b
--- /dev/null
+++ b/build/tmp/compileJava/source-classes-mapping.txt
@@ -0,0 +1,4 @@
+models/PingPong.java
+ models.PingPong
+App.java
+ App
diff --git a/gradle/wrapper/gradle-wrapper.jar b/gradle/wrapper/gradle-wrapper.jar
new file mode 100644
index 0000000..94336fc
Binary files /dev/null and b/gradle/wrapper/gradle-wrapper.jar differ
diff --git a/out/production/classes/App.class b/out/production/classes/App.class
new file mode 100644
index 0000000..ffd36d9
Binary files /dev/null and b/out/production/classes/App.class differ
diff --git a/out/production/classes/models/PingPong.class b/out/production/classes/models/PingPong.class
new file mode 100644
index 0000000..4dd243f
Binary files /dev/null and b/out/production/classes/models/PingPong.class differ
diff --git a/out/test/classes/AppTest.class b/out/test/classes/AppTest.class
new file mode 100644
index 0000000..5055821
Binary files /dev/null and b/out/test/classes/AppTest.class differ
diff --git a/out/test/classes/models/PingPongTest.class b/out/test/classes/models/PingPongTest.class
new file mode 100644
index 0000000..fdf201c
Binary files /dev/null and b/out/test/classes/models/PingPongTest.class differ
diff --git a/src/main/java/App.java b/src/main/java/App.java
index e683e21..0871416 100644
--- a/src/main/java/App.java
+++ b/src/main/java/App.java
@@ -1,3 +1,24 @@
-public class App {
+import models.PingPong;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.util.ArrayList;
 
-}
+public class App {
+    public static void main(String[] args) {
+        BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(System.in));
+        System.out.println("I'm a ping-pong application!");
+        System.out.println("Enter a number:");
+        try {
+            String stringUserNumber = bufferedReader.readLine();
+            int intUserNumber = Integer.parseInt(stringUserNumber);
+            PingPong pingPong = new PingPong();
+            ArrayList<Object> pingPongResult = pingPong.runPingPong(intUserNumber);
+            System.out.println(pingPongResult);
+        }
+        catch (IOException e){
+            e.printStackTrace();
+        }
+    }
+}
\ No newline at end of file
diff --git a/src/main/java/models/PingPong.java b/src/main/java/models/PingPong.java
index 63249c7..c240039 100644
--- a/src/main/java/models/PingPong.java
+++ b/src/main/java/models/PingPong.java
@@ -1,5 +1,6 @@
 package models;
 
+
 import java.util.ArrayList;
 import java.util.List;
 
@@ -7,6 +8,18 @@ public class PingPong {
 
     public ArrayList<Object> runPingPong(int countUpTo){
         ArrayList<Object> result = new ArrayList<Object>();
-        return null;
+        for (int i = 1; i <= countUpTo; i++){
+            if (i % 3 == 0 && i % 5 == 0){
+                result.add("pingpong");
+            } else if (i % 3 == 0){
+                result.add("ping");
+            } else if (i % 5 == 0){
+                result.add("pong");
+            } else {
+                result.add(i);
+            }
+        }
+        return result;
     }
+
 }
\ No newline at end of file
diff --git a/src/test/java/AppTest.java b/src/test/java/AppTest.java
new file mode 100644
index 0000000..e130a20
--- /dev/null
+++ b/src/test/java/AppTest.java
@@ -0,0 +1,5 @@
+import static org.junit.Assert.*;
+
+public class AppTest {
+
+}
\ No newline at end of file
diff --git a/src/test/java/models/PingPongTest.java b/src/test/java/models/PingPongTest.java
index 33140c7..34d0640 100644
--- a/src/test/java/models/PingPongTest.java
+++ b/src/test/java/models/PingPongTest.java
@@ -1,16 +1,69 @@
 package models;
 
-import org.junit.*;
-import static org.junit.Assert.*;
+import org.junit.Test;
+
 import java.util.ArrayList;
-import java.util.List;
+
+import static org.junit.Assert.assertEquals;
 
 public class PingPongTest {
+
     @Test
     public void runPingPong_countUpToOne_ArrayList() {
         PingPong testPingPong = new PingPong();
-        List<Object> expectedOutput = new ArrayList<Object>();
+        ArrayList<Object> expectedOutput = new ArrayList<Object>();
         expectedOutput.add(1);
         assertEquals(expectedOutput, testPingPong.runPingPong(1));
     }
-}
\ No newline at end of file
+
+    @Test
+    public void runPingPong_countUpToGivenNumber_ArrayList() throws Exception {
+        PingPong testPingPong = new PingPong();
+        ArrayList<Object> expectedOutput = new ArrayList<Object>();
+        expectedOutput.add(1);
+        expectedOutput.add(2);
+        assertEquals(expectedOutput, testPingPong.runPingPong(2));
+    }
+    @Test
+    public void runPingPong_replaceMultiplesOf3_ArrayList() {
+        PingPong testPingPong = new PingPong();
+        ArrayList<Object> expectedOutput = new ArrayList<Object>();
+        expectedOutput.add(1);
+        expectedOutput.add(2);
+        expectedOutput.add("ping");
+        assertEquals(expectedOutput, testPingPong.runPingPong(3));
+    }
+    @Test
+    public void runPingPong_replaceMultiplesOf5_ArrayList() {
+        PingPong testPingPong = new PingPong();
+        ArrayList<Object> expectedOutput = new ArrayList<Object>();
+        expectedOutput.add(1);
+        expectedOutput.add(2);
+        expectedOutput.add("ping");
+        expectedOutput.add(4);
+        expectedOutput.add("pong");
+        assertEquals(expectedOutput, testPingPong.runPingPong(5));
+    }
+    @Test
+    public void runPingPong_replaceMultiplesOfBoth3And5_ArrayList() {
+        PingPong testPingPong = new PingPong();
+        ArrayList<Object> expectedOutput = new ArrayList<Object>();
+        expectedOutput.add(1);
+        expectedOutput.add(2);
+        expectedOutput.add("ping");
+        expectedOutput.add(4);
+        expectedOutput.add("pong");
+        expectedOutput.add("ping");
+        expectedOutput.add(7);
+        expectedOutput.add(8);
+        expectedOutput.add("ping");
+        expectedOutput.add("pong");
+        expectedOutput.add(11);
+        expectedOutput.add("ping");
+        expectedOutput.add(13);
+        expectedOutput.add(14);
+        expectedOutput.add("pingpong");
+        assertEquals(expectedOutput, testPingPong.runPingPong(15));
+    }
+}
+