#if __has_include(<yoniha/all.h>)
#include <yoniha/all.h>
using namespace atcoder;
#else
#include <bits/stdc++.h>
#if __has_include(<atcoder/all>)
#include <atcoder/all>
using namespace atcoder;
#endif
#endif
using namespace std;

#define int long long
#define all(x) (x).begin(), (x).end()
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define rrep(i, n) for(int i = (int)((n) - 1); i >= 0; i--)
template <typename T> bool chmax(T &a,const T &b){if(a<b){a=b;return true;}return false;}
template <typename T> bool chmin(T &a,const T &b){if(a>b){a=b;return true;}return false;}

// using mint = modint;

signed main(){
  int n, m; cin >> n >> m;
  vector g(n, vector<int>(0));
  while(m--){
    int u, v; cin >> u >> v; u--; v--;
    g.at(u).emplace_back(v);
    g.at(v).emplace_back(u);
  }
  int k; cin >> k;
  vector<bool> iwai(n, false);
  while(k--){
    int a; cin >> a; a--;
    iwai.at(a) = true;
  }
  vector<int> seen(5 * n, -1); seen.at(0) = 0;
  deque<int> bfs; bfs.emplace_back(0);
  while(!bfs.empty()){
    int from = bfs.front(); bfs.pop_front();
    for(auto t : g.at(from % n)){
      int to = t + (iwai.at(t) ? from / n * n + n : 0);
      if(to >= 5 * n || seen.at(to) != -1) continue;
      seen.at(to) = seen.at(from) + 1;
      bfs.emplace_back(to);
    }
  }
  int ans = 1ll << 60;
  rep(i, 5) if(seen.at(n - 1 + i * n) != -1) chmin(ans, seen.at(n - 1 + i * n));
  // rep(i, 5) cout << seen.at(n - 1 + i * n) << '\n';
  cout << (ans == 1ll << 60 ? -1 : ans) << '\n';
}
/*
頂点を5倍にする？
streakを途切れさせる処理を入れていない
*/