#include <bits/stdc++.h>
#include <cstdlib>
#include <math.h>
using namespace std;

using ll = long long;


int main(){
    int n,m;
    cin >> n >> m;
    vector<vector<int>>g(n);
    vector<bool>a(n);
    for(int i=0;i<m;i++){
        int u,v;
        cin >> u >> v;
        u--;v--;
        g[u].push_back(v);
        g[v].push_back(u);
    }
    int k;
    cin >> k;
    for(int i=0;i<k;i++){
        int x;
        cin >> x;
        x--;
        a[x]=true;
    }
    vector dist(n,vector<int>(5,-1));
    dist[0][0]=0;
    queue<pair<int,int>>q;
    q.push({0,0});
    while(!q.empty()){
        auto [x,d]=q.front();q.pop();
        for(int y:g[x]){
            int nd=0;
            if(a[y]){
                nd=d+1; 
            }
            if(nd==5)continue;
            if(dist[y][nd]!=-1)continue;
            dist[y][nd]=dist[x][d]+1;
            q.push({y,nd});
        }
    }
    cout << dist[n-1][0] << endl;
    return 0;
}