int[,] dist = new int[idNode, idNode];
            for (int i = 0; i < idNode; i++)
            {
                for (int j = 0; j < idNode; j++)
                {
                    dist[i, j] = idNode + 1;
                }
            }
            for (int i = 0; i < idNode; i++ )
            {
                dist[i, i] = 0;
            }
            for (int i = 0; i < idNode; i++)
            {
                for (int j = 0; j < idNode; j++)
                {
                    if (matrixGraph[i, j] == 1)
                        dist[i, j] = 1;
                }
            }

                for (int k = 0; k < idNode; k++)
                {
                    for (int i = 0; i < idNode; i++)
                    {
                        for (int j = 0; j < idNode; j++)
                        {
                            if (dist[i, j] > dist[i, k] + dist[k, j])
                            {
                                dist[i, j] = dist[i, k] + dist[k, j];
                            }
                        }
                    }
                }
            int max = 0;
            for (int i = 0; i < idNode; i++)
                for (int j = 0; j < idNode; j++ )
                {
                    int tmp = dist[i, j];
                    if (tmp > max)
                        max = tmp;
                }
            return max;