// 一番狂気を感じた
#include <bits/stdc++.h>
using namespace std;
// #include <atcoder/modint>
// using namespace atcoder;
// using mint = modint998244353;
using ll = long long;
#define fix(x) fixed << setprecision(x)
#define rep(i, n) for(int i = 0; i < n; ++i)
#define all(x) (x).begin(),(x).end()
template<class T>bool chmin(T&a, const T&b){if(a>b){a=b;return 1;}return 0;}
template<class T>bool chmax(T&a, const T&b){if(a<b){a=b;return 1;}return 0;}
constexpr ll INFLL = (1LL << 62), MOD = 998244353;
constexpr int INF = (1 << 30);

int main(){
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    int n,m;
    cin >> n >> m;
    vector<vector<int>> g(n);
    rep(i,m){
        int u,v;
        cin >> u >> v;
        --u, --v;
        g[u].emplace_back(v);
        g[v].emplace_back(u);
    }
    vector<bool> yiwiy9(n,false);
    int k;
    cin >> k;
    while(k--){
        int a;
        cin >> a;
        yiwiy9[a-1] = true;
    }
    vector<vector<int>> dist(n,vector<int>(5,INF));
    dist[0][0] = 0;
    queue<pair<int,int>> que;
    que.emplace(0,0);
    while(que.size()){
        auto [p,q] = que.front();
        if(p==n-1){
            cout << dist[p][q] << '\n';
            return 0;
        }
        que.pop();
        for(int x:g[p]){
            int r = yiwiy9[x]?q+1:0;
            if(r>4) continue;
            if(chmin(dist[x][r], dist[p][q]+1)) que.emplace(x,r);
        }
    }
    cout << "-1\n";
    return 0;
}