Unhappy [Q] Help Debugging my app!!!!!! im so noob -_-

Hi Guys, i'm having a training to develop android apps, the training i found in developer.android.com
the thing is that i'm now in page "Building a Simple User Interface" and i just completed it and now the problem is that i can't run the app cause of:
"container cannot be resolved or not a field"
what the hell is this???
i'm noob here by the way
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