#include <bits/stdc++.h>
#include <atcoder/lazysegtree>
using namespace std;
using ll = long long;
const int INF = 1001001001;
const ll LINF = 3001001001001001001;
const int MOD = 998244353;
const string Yes = "Yes";
const string No = "No";
#define reps(i, a, n) for (ll i = (a); i < (ll)(n); ++i)
#define rep(i, n) reps(i, 0, n)
#define all(a) (a).begin(), (a).end()
#define rall(a) (a).rbegin(), (a).rend()
template<typename T> bool chmin(T& a, T b){if(a > b){a = b; return true;} return false;}
template<typename T> bool chmax(T& a, T b){if(a < b){a = b; return true;} return false;}
template <typename T> istream &operator>>(istream &is, vector<T> &v) {for (T &in : v)is >> in;return is;}
vector<pair<int,int>> dir = {{0,1},{1,0},{0,-1},{-1,0},};

int main() {
  int n,m;cin>>n>>m;
  vector<vector<int>> g(n,vector<int>());
  rep(i,m) {
    int u,v;cin>>u>>v;u--;v--;
    g.at(u).push_back(v);
    g.at(v).push_back(u);
  }
  int k;cin>>k;
  set<int> st;
  rep(i,k) {
    int a;cin>>a;a--;st.insert(a);
  }
  vector<vector<int>> dists(n,vector<int>(5,INF));
  dists.at(0).at(0) = 0;
  queue<pair<int,int>> q;
  q.push({0,0});
  while(q.size()) {
    int v = q.front().first;
    int cnt = q.front().second;
    q.pop();
    for(auto nv : g.at(v)) {
      int ncnt = st.count(nv)?cnt+1:0;
      if(ncnt>=5) continue;
      if(dists.at(nv).at(ncnt)!=INF) continue;
      q.push({nv,ncnt});
      dists.at(nv).at(ncnt) = dists.at(v).at(cnt) + 1;
    }
  }
  int ans = INF;
  rep(i,5) {
    chmin(ans,dists.at(n-1).at(i));
  }
  if(ans==INF) ans = -1;
  cout << ans << endl;
  
  return 0;
}