Android Unable to merge android manifest Error

Hello I'm Korean high school student's. I finish making games, but I can't build project Because of merge android manifest Error. I'm not expert programmer, and Korean internet cafe do not solve this error..

I'm use 5.3.5f ver, and I want use google in app purchasing

I wan't finish my project. Please help me Professional Programmers.. And I am sorry that I can't use english well because I am a Korean student. here is error code

 Error: [Temp\StagingArea\AndroidManifest-main.xml:13, C:\Users\Administrator\Desktop\World destroy - ENGLISH\Temp\StagingArea\android-libraries\unityads-release\AndroidManifest.xml:9] Trying to merge incompatible /manifest/application/activity[@name=com.unity3d.ads.android.view.UnityAdsFullscreenActivity] element:
 
 UnityEditor.HostView:OnGUI()
 
 
 
 
 CommandInvokationFailure: Unable to merge android manifests. See the Console for more details. 
 C:/Program Files (x86)/Java/jdk1.8.0_71\bin\java.exe -Xmx1024M -Dcom.android.sdkmanager.toolsdir="D:/SDK\tools" -Dfile.encoding=UTF8 -jar "C:\Program Files\Unity\Editor\Data\PlaybackEngines\AndroidPlayer/Tools\sdktools.jar" -
 
 stderr[
 Error: [Temp\StagingArea\AndroidManifest-main.xml:13, C:\Users\Administrator\Desktop\World destroy - ENGLISH\Temp\StagingArea\android-libraries\unityads-release\AndroidManifest.xml:9] Trying to merge incompatible /manifest/application/activity[@name=com.unity3d.ads.android.view.UnityAdsFullscreenActivity] element:
   <activity
       @android:name="com.unity3d.ads.android.view.UnityAdsFullscreenActivity"
 --    @tools:ignore="UnusedAttribute"
 --    @xmlns:tools="tools">
 --</activity>
   <activity
       @android:name="com.unity3d.ads.android.view.UnityAdsFullscreenActivity"
 ++    @tools:ignore="UnusedAttribute">
 ++</activity>
 ++(end reached)
 ]
 stdout[
 [Temp\StagingArea\AndroidManifest-main.xml:12, C:\Users\Administrator\Desktop\World destroy - ENGLISH\Temp\StagingArea\android-libraries\GooglePlay\AndroidManifest.xml:9] Skipping identical /manifest/application/activity[@name=com.unity.purchasing.googleplay.PurchaseActivity] element.
 ]
 UnityEditor.Android.Command.Run (System.Diagnostics.ProcessStartInfo psi, UnityEditor.Android.WaitingForProcessToExit waitingForProcessToExit, System.String errorMsg)
 UnityEditor.Android.AndroidSDKTools.RunCommandInternal (System.String javaExe, System.String sdkToolsDir, System.String[] sdkToolCommand, Int32 memoryMB, System.String workingdir, UnityEditor.Android.WaitingForProcessToExit waitingForProcessToExit, System.String errorMsg)
 UnityEditor.Android.AndroidSDKTools.RunCommandSafe (System.String javaExe, System.String sdkToolsDir, System.String[] sdkToolCommand, Int32 memoryMB, System.String workingdir, UnityEditor.Android.WaitingForProcessToExit waitingForProcessToExit, System.String errorMsg)
 UnityEditor.HostView:OnGUI()
 
 
 
 
 
 Error building Player: CommandInvokationFailure: Unable to merge android manifests. See the Console for more details. 
 C:/Program Files (x86)/Java/jdk1.8.0_71\bin\java.exe -Xmx1024M -Dcom.android.sdkmanager.toolsdir="D:/SDK\tools" -Dfile.encoding=UTF8 -jar "C:\Program Files\Unity\Editor\Data\PlaybackEngines\AndroidPlayer/Tools\sdktools.jar" -
 
 stderr[
 Error: [Temp\StagingArea\AndroidManifest-main.xml:13, C:\Users\Administrator\Desktop\World destroy - ENGLISH\Temp\StagingArea\android-libraries\unityads-release\AndroidManifest.xml:9] Trying to merge incompatible /manifest/application/activity[@name=com.unity3d.ads.android.view.UnityAdsFullscreenActivity] element:
   <activity
       @android:name="com.unity3d.ads.android.view.UnityAdsFullscreenActivity"
 --    @tools:ignore="UnusedAttribute"
 --    @xmlns:tools="tools">
 --</activity>
   <activity
       @android:name="com.unity3d.ads.android.view.UnityAdsFullscreenActivity"
 ++    @tools:ignore="UnusedAttribute">
 ++</activity>
 ++(end reached)
 ]
 stdout[
 [Temp\StagingArea\AndroidManifest-main.xml:12, C:\Users\Administrator\Desktop\World destroy - ENGLISH\Temp\StagingArea\android-libraries\GooglePlay\AndroidManifest.xml:9] Skipping identical /manifest/application/activity[@name=com.unity.purchasing.googleplay.PurchaseActivity] element.
 ]