public static int Lonely(int[,] a, int num)
        {
            int found;
            for (int i = 1; i < a.GetLength(0) - 1; i++)
            {
                found = 0;
                for (int k = 1; k < a.GetLength(1) - 1; k++)
                {
                    if (a[i, k] == num)
                    {
                        for (int m = i - 1; m < i + 2; m++)
                        {
                            for (int j = k - 1; j < k + 2; j++)
                            {
                                if (a[i, k] == a[m, j] && m != i && j != k)
                                    found++;
                            }
                        }
                        if(found == 0)
                           return 1;
                    }
                }
            }
            return 0;
        }