Поиск длины кратчайшего маршрута между вершинами s и d графа

class GraphM
 
{
 
int[,] G; int n; int nM; int[] mark;
 
public GraphM(int nt, int [,] g,int s,int d)
 
{
 
n=nt;
 
G=new int[n,n];
 
for (int i = 0; i < n; i++)
 
for (int j = 0; j < n; j++) G[i, j] = g[i, j];
 
mark = new int[nt];
 
for (int i = 0; i < n; i++)
 
mark[i] = 0;
 
nM = 0;
 
nM = bfsM(s,d);
 
}
 
int bfsM(int s,int d)
 
{
 
Queue<int> Q,M; mark[s] = 1; int vt = s;
 
Q = new Queue<int>();
 
M= new Queue<int>();
 
Q.Enqueue(vt); M.Enqueue(0);
 
int nMt;
 
while (true) {
 
vt=Q.Dequeue();
 
nMt=M.Dequeue(); . . . }
 
nM = nMt;
 
return nM;
 
}
 
public override string ToString()
 
{. . . }
 
}
 
class Program
 
{
 
static void Main(string[] args)
 
{
 
StreamReader R = new StreamReader("in.txt");
 
StreamWriter W = new StreamWriter("out.txt");
 
int i;int[,] A;string[] As; int n; int s,d;
 
As = R.ReadLine().Split();
 
n = As.Length;
 
A = new int[n,n];
 
i=0;
 
for (int j = 0; j < n; j++) A[i,j] = Convert.ToInt32(As[j]);
 
for (i++; i < n; i++) {
 
As = R.ReadLine().Split();
 
for (int j = 0; j < n; j++) A[i, j] = Convert.ToInt32(As[j]);
 
}
 
As = R.ReadLine().Split();
 
s=Convert.ToInt32(As[0]);
 
d=Convert.ToInt32(As[1]);
 
GraphM oG = new GraphM(n, A,s,d);
 
W.WriteLine(oG);
 
R.Close();
 
W.Close();
 
}
 
}