#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int i = 0; i < (n); ++i)
using ll = long long;
using ull = unsigned long long;

int main() {
  cin.tie(nullptr)->sync_with_stdio(false);
  int n, m;
  cin >> n >> m;
  vector<pair<int, int>> edges(m);
  rep(i, m) {
    int u, v;
    cin >> u >> v;
    --u, --v;
    edges[i] = { u, v };
  }
  int k;
  cin >> k;
  set<int> p;
  rep(i, k) {
    int x;
    cin >> x;
    --x;
    p.insert(x);
  }
  vector Graph(6 * n, vector<int>());
  for (auto [u, v] : edges) {
    rep(x, 5) {
      int nu = u + n * x, nv = v + n * (p.contains(v) ? x + 1 : 0);
      Graph[nu].push_back(nv);
    }
    rep(x, 5) {
      int nv = v + n * x, nu = u + n * (p.contains(u) ? x + 1 : 0);
      Graph[nv].push_back(nu);
    }
  }
  constexpr int INF = 1e9;
  vector<int> dist(6 * n, INF);
  dist[0] = 0;
  queue<int> q;
  q.push(0);
  while (!q.empty()) {
    int u = q.front();
    q.pop();
    for (int v : Graph[u]) {
      if (dist[v] > dist[u] + 1) {
        dist[v] = dist[u] + 1;
        q.push(v);
      }
    }
  }
  int ans = INF;
  rep(x, 6) ans = min(ans, dist[(n - 1) + n * x]);
  if (ans == INF) ans = -1;
  cout << ans << '\n';
  return 0;
}