#include<bits/stdc++.h>
using namespace std;
#define rep(i, N) for(i = 0; i < N; i++)
#define ll long long

int main(void) {
    ll N,M;
    set<ll>con[100009];
    bool T[100009]={0};
    
    ll i, j, k;

    cin>>N>>M;
    rep(i,M){
        ll a,b;
        cin>>a>>b;
        con[a].insert(b);
        con[b].insert(a);
    }
    ll K;cin>>K;
    rep(i,K){
        ll t; cin>>t;
        T[t] = true;
    }

    ll dist[100009][6];
    rep(i,N+1)rep(j,6)dist[i][j]=INT64_MAX;
    queue<pair<ll,ll>>q;
    q.push({1,0});
    dist[1][0]=0;
    while(!q.empty()){
        auto p = q.front(); q.pop();
        ll v = p.first;
        ll c = p.second;
        for(auto nv: con[v]){
            ll nc;
            if(T[nv])nc=c+1;
            else nc=0;
            if(nc>=5)continue;
            if(dist[nv][nc] > dist[v][c] + 1){
                dist[nv][nc] = dist[v][c] + 1;
                q.push({nv,nc});
            }
        }
    }

    ll ans=INT64_MAX;
    rep(i,6)ans=min(ans,dist[N][i]);
    if(ans==INT64_MAX)ans=-1;

    cout<<ans<<endl;

    return 0;
}