#include<bits/stdc++.h>
namespace {
#pragma GCC diagnostic ignored "-Wunused-function"
#include<atcoder/all>
#pragma GCC diagnostic warning "-Wunused-function"
using namespace std;
using namespace atcoder;
#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--)
#define all(x) begin(x), end(x)
#define rall(x) rbegin(x), rend(x)
template<class T> bool chmax(T& a, const T& b) { if (a < b) { a = b; return true; } else return false; }
template<class T> bool chmin(T& a, const T& b) { if (b < a) { a = b; return true; } else return false; }
using ll = long long;
using P = pair<int,int>;
using VI = vector<int>;
using VVI = vector<VI>;
using VL = vector<ll>;
using VVL = vector<VL>;

vector<int> bfs(const vector<vector<int>>& g, int s=0) {
  const int n = g.size();
  vector<int> dist(n, -1);
  vector<int> q(n);
  q[0] = s;
  dist[s] = 0;
  int l = 0, r = 1;
  while(l < r) {
    int u = q[l++];
    int nd = dist[u] + 1;
    for(int v: g[u]) if (dist[v] == -1) {
      dist[v] = nd;
      q[r++] = v;
    }
  }
  return dist;
}
} int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int n, m;
  cin >> n >> m;
  vector<P> es(m);
  for (auto& [u, v] : es) cin >> u >> v, u--, v--;
  int k;
  cin >> k;
  vector<char> exists(n);
  rep(_, k) {
    int a;
    cin >> a;
    exists[a - 1] = true;
  }
  VVI to(5 * n);
  for (auto [u, v] : es) {
    rep(_, 2) {
      if (exists[v]) {
        rep(k, 4) to[u + k * n].emplace_back(v + (k + 1) * n);
      } else {
        rep(k, 5) to[u + k * n].emplace_back(v);
      }
      swap(u, v);
    }
  }
  auto dist = bfs(to, 0);
  constexpr int INF = 1001001001;
  int ans = INF;
  rep(k, 5) if (int d = dist[n-1+k*n]; d != -1) chmin(ans, d);
  if (ans == INF) ans = -1;
  cout << ans << '\n';
}