google analytics and admob , I hava some problems

[minezjob]

First, I first imported admob's sdk after the ad was written. I wanted to analyze the number of users' click ads, so I then imported the google analytic, however, the following error occurred during the package APK because the jar package was in conflict? But I do not know how to find the package of conflicts. I use the version of unity5.5.3. Problem description may be a bit strange, because I am a Chinese student, over the wall to find the answer. If you know the solution, please reply me in time. And do not write that hard to understand, after all, Google Translate do not understand our jargon, thank you.

[minezjob]

CommandInvokationFailure: Unable to convert classes into dex format.
C:/Program Files/Java/jdk1.8.0_151\bin\java.exe -Xmx2048M -Dcom.android.sdkmanager.toolsdir="C:/Users/zj/AppData/Local/Android/android-sdk\tools" -Dfile.encoding=UTF8 -jar "C:\Program Files\Unity\Editor\Data\PlaybackEngines\AndroidPlayer/Tools\sdktools.jar" -

stderr[

trouble writing output: Too many field references to fit in one dex file: 69213; max is 65536.
You may try using multi-dex. If multi-dex is enabled then the list of classes for the main dex list is too large.
References by package:
2 android.accounts
26 android.app
1 android.content
38 android.content.pm
9 android.content.res
3 android.database
41 android.graphics
2 android.media
1 android.media.browse
2 android.net
21 android.os
3 android.print
........