private int quad_value(int x, int y, int player) {
      int counter = 0;
      if (checker_of(player,x,y))
        counter++;
      if (checker_of(player,x,y+1))
        counter++;
      if (checker_of(player,x+1,y))
        counter++;
      if (checker_of(player,x+1,y+1))
        counter++;
      if (counter == 2 && ((checker_of(player,x,y) && checker_of(player,x+1,y+1))
                           || (checker_of(player,x+1,y) && checker_of(player,x,y+1))))
        return 5;
      return counter;
    }