dij洛谷电车

//Gang
#include<iostream>
#include<cstring>
#include<algorithm>
#include<cstdio>
#include<cstdlib>
#include<cmath>
#define FOR(x,y,z) for(int x=y;x<=z;x++)
#define REP(x,y,z) for(int x=y;x>=z;x--)
#define INF 99999999
#define ll long long
];
];
][], n, a, b;
int v, u;
int temp;
using namespace std;
int main()
{
    scanf("%d %d %d", &n, &a, &b);
    FOR(i, , n)
        FOR(j, , n)
        {
        ;
        else e[i][j] = INF;
        }
    FOR(i, , n)
    {
        scanf("%d", &v);
        FOR(j, , v)
        {
            scanf("%d", &u);
            )e[i][u] = ;
            ;
        }
    }
    FOR(i, , n)
    {
    dis[i] = e[a][i];
    //book[i] = 0;
    }
    book[a] = ;
    FOR(i, , n - )
    {
        int Min = INF;
        FOR(j, , n)
        {
             && dis[j] < Min)
            {
                Min = dis[j];
                temp = j;
            }
        }
        book[temp] = ;
        FOR(h, , n)
        {
            if (e[temp][h] != INF && !book[h])
            {
                if (dis[h] > dis[temp] + e[temp][h])
                    dis[h] = dis[temp] + e[temp][h];
            }
        }
    }
    printf(:dis[b]);
    ;
}