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

vector<int> BFS(vector<vector<int>> &Graph,int start){
    int N = Graph.size();
    vector<int> ret(N,-1);
    queue<int> Q;
    ret.at(start) = 0,Q.push(start);
    while(Q.size()){
        int pos = Q.front(); Q.pop();
        for(auto to : Graph.at(pos)){
            if(ret.at(to) != -1) continue;
            ret.at(to) = ret.at(pos)+1;
            Q.push(to);
        }
    }
    return ret;
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);

    int N,M; cin >> N >> M;
    vector<pair<int,int>> UV(M);
    for(auto &[u,v] : UV) cin >> u >> v,u--,v--;
    int K; cin >> K;
    vector<bool> NG(N);
    while(K--){
        int a; cin >> a;
        NG.at(a-1) = true;
    }

    vector<vector<int>> Graph(N*5);
    for(auto [u,v] : UV){
        for(int k=0; k<5; k++){
            if(NG.at(v)){
                if(k < 4) Graph.at(u+k*N).push_back(v+k*N+N);
            }
            else Graph.at(u+k*N).push_back(v);
            swap(u,v);
            if(NG.at(v)){
                if(k < 4) Graph.at(u+k*N).push_back(v+k*N+N);
            }
            else Graph.at(u+k*N).push_back(v);
            swap(u,v);
        }
    }

    auto dist = BFS(Graph,0);
    int answer = 1001001001;
    for(int i=0; i<5; i++){
        if(dist.at(N-1+i*N) != -1) answer = min(answer,dist.at(N-1+i*N));
    }
    if(answer > 1e9) answer = -1;
    cout << answer << endl;

}