public class GameActivity {
   int value;
   Button button;
   @Override
   protected void OnCreate(Bundle savedInstenceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_game);

      value = 1;
      button = (Button) findViewById(R.id.button);
      button.setOnClickListner(new View.OnClickListner() {
         @Override
         public void onClick(View view) {
            value++;
         }
      });
}