C++ :

#include <iostream> 
#include <cstdio>
#include <cstring>
#define foru(i, l, r) for (int i = l; i <= r; i ++)
using namespace std; 

const int N = 510;
int m, n, e[N][N], a[N];
bool vst[N];

void dijkstra() {
	vst[1] = true;
	
	foru (i, 2, n) {
		int t = 0;
		foru (j, 1, n) {
			if (!vst[j] && e[1][j] < e[1][t]) t = j;
		}
		vst[t] = true;
		
		foru (j, 1, n) {
			if (!vst[j]) e[1][j] = min(e[1][j], e[1][t]+e[t][j]);
		}
	}
}

int main() {
	scanf("%d%d\n", &m, &n);
 	memset(e, 0x3f, sizeof(e));
 	
 	while (m--) {
 		int num = 0, cnt = 0;
 		char ch;
 		while (scanf("%c", &ch)) {
			if (ch>='0' && ch<='9') {
				num = num*10 + ch-'0';
			}
			else {
				a[++cnt] = num;
				num = 0;
 				if (ch == '\n') break;
			}
		}
		
 		foru (i, 1, cnt) {
 			foru (j, i+1, cnt) {
 				e[a[i]][a[j]] = 1;
			}
 		}
	}
	
	dijkstra();
	
	if (e[1][n] == 0x3f3f3f3f) cout << "NO";
	else cout << e[1][n] - 1;
	
	return 0;
}

Pascal :

const
  maxn=500;
var
  a:array[1..maxn,1..maxn]of integer;
  b:array[1..maxn]of boolean;
  t:array[1..maxn]of longint;
  x,y,i,j,max,k,m,n:integer;
begin
  readln(m,n);
  fillchar(a,sizeof(a),0);
  y:=0;
  for i:=1 to m do
  begin
	fillchar(t,sizeof(t),0);
	while not eoln do
        begin
          inc(y);
          read(t[y]);
        end;
      readln;
      for j:=1 to y-1 do
        for k:=j+1 to y do
          a[t[j],t[k]]:=1;
    end;
  fillchar(b,sizeof(b),false);
  b[1]:=true;
  for i:=2 to n do
    begin
      max:=maxint;
      for j:=1 to n do
        if(not b[j])and(a[1,j]<>0)and(a[1,j]<max)then begin max:=a[1,j]; x:=j; end;
      b[x]:=true;
      for j:=2 to n do
        if(a[1,x]<>0)and(a[x,j]<>0)then
          if(a[1,j]=0)or(a[1,j]>a[1,x]+a[x,j])then
            a[1,j]:=a[1,x]+a[x,j];
    end;
  if a[1,n]-1=-1 then write('NO')
                 else write(a[1,n]-1);
end.