public static int change(int row, int col, int[] mm) {
		int c = ((mm[row] & (1 << col)) != 0 ? -1 : 1);
		if (col - 1 >= 0) {
			c += ((mm[row] & (1 << (col - 1))) != 0 ? -1 : 1);
			mm[row] ^= 1 << (col - 1);
		}
		if (col + 1 < 10) {
			c += ((mm[row] & (1 << (col + 1))) != 0 ? -1 : 1);
			mm[row] ^= 1 << (col + 1);
		}
		if (row + 1 < 10) {
			c += ((mm[row + 1] & (1 << col)) != 0 ? -1 : 1);
			mm[row + 1] ^= 1 << col;
		}
		return c;
	}