void UnmakeMove()
 {
     if (sm.CanPlay(false))
     {
         turn--;
         wm.TurnChange((turn % 3) + 1);
         if (winner != 0)
         {
             wm.UndoWin();
         }
         winner = 0;
         int move = gm.DeregisterMove();
         sm.DeSpawnSequence(move);
     }
 }