#include <bits/stdc++.h>
using namespace std;
// #include<atcoder/all>
// using mint = atcoder::modint998244353;
using ld = long double;
#define fi first
#define se second
#define all(x) x.begin(),x.end()
#define rep(i,n) for(int i=0;i<(int)(n);++i)
template<typename T>bool chmin(T&a,T b){return b<a?(a=b,1):0;}
template<typename T>bool chmax(T&a,T b){return b>a?(a=b,1):0;}

int main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    
    int N,M;
    cin>>N>>M;
    vector<vector<int>> G(N);
    rep(i,M){
        int u,v;
        cin>>u>>v;
        u--;v--;
        G[u].push_back(v);
        G[v].push_back(u);
    }
    int K;
    cin>>K;
    vector<int> A(N,0);
    rep(i,K){
        int a;
        cin>>a;
        a--;
        A[a]=1;
    }

    queue<pair<int,int>> q;
    vector dp(N,vector<int>(5,1e9));
    dp[0][0]=0;
    q.push({0,0});
    while(!q.empty()){
        auto [v,k]=q.front();
        q.pop();
        for(int e: G[v]){
            int x=k;
            if(A[e]) x++;
            else x=0;
            if(x==5) continue;
            if(dp[e][x]!=1e9) continue;
            dp[e][x]=dp[v][k]+1;
            q.push({e,x});
        }
    }
    int ans=1e9;
    rep(i,5) chmin(ans, dp[N-1][i]);
    if(ans==1e9) ans=-1;
    cout<<ans<<"\n";


}