#include <bits/stdc++.h>
#include <atcoder/all>
using namespace atcoder;
using namespace std;

typedef long long ll;
typedef long double ld;
typedef unsigned long long ull;
#define ALL(a) (a).begin(), (a).end()
#define rep(i, n) for (ll i = 0; i < (n); ++i)
#define rrep(i, n) for (ll i = (n) - 1; i >= 0; --i)
#define foreach(i, n) for (auto i : (n))
#define chmax(a, b) a = max(a, b)
#define chmin(a, b) a = min(a, b)
#define popcount __builtin_popcountll

using mint = modint998244353;
using mint1 = modint1000000007;

template <typename K, typename V>
using umap = std::unordered_map<K, V>;
template <typename K>
using uset = std::unordered_set<K>;

// 参考元 : https://qiita.com/ganyariya/items/df35d253726269bda436
struct HashPair {
    
    //注意 constがいる
    template<class T1, class T2>
    size_t operator()(const pair<T1, T2> &p) const {
        
        //first分をハッシュ化する
        auto hash1 = hash<T1>{}(p.first);
        
        //second分をハッシュ化する
        auto hash2 = hash<T2>{}(p.second);
        
        //重複しないようにハッシュ処理
        size_t seed = 0;
        seed ^= hash1 + 0x9e3779b9 + (seed << 6) + (seed >> 2);
        seed ^= hash2 + 0x9e3779b9 + (seed << 6) + (seed >> 2);
        return seed;
    }
};
template <typename X, typename Y>
using pair_map = unordered_map<pair<X, Y>, ll, HashPair>;

template <typename X, typename Y>
using pair_set = unordered_set<pair<X, Y>, HashPair>;

template <typename T>
using v = vector<T>;
template <typename T>
using vv = v<v<T>>;
template <typename T>
using vvv = vv<v<T>>;

template <typename T, typename U>
using P = pair<T, U>;

using grid = vector<vector<char>>;
using graph = vector<vector<int>>;
using vi = vector<int>; using vvi = vector<vector<int>>; using vvvi = vector<vector<vector<int>>>;
using vl = vector<ll>; using vvl = vector<vector<ll>>; using vvvl = vector<vector<vector<ll>>>;
using vm = vector<mint>; using vvm = vector<vector<mint>>; using vvvm = vector<vector<vector<mint>>>;
using vm1 = vector<mint1>; using vvm1 = vector<vector<mint1>>; using vvvm1 = vector<vector<vector<mint1>>>;
using vld = vector<ld>; using vvld = vector<vector<ld>>; using vvvld = vector<vector<vector<ld>>>;
using vb = vector<bool>; using vvb = vector<vector<bool>>;
using vs = vector<string>; using vvs = vector<vector<string>>;

int main()
{
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    ll n, m;
    cin >> n >> m;
    graph g(n);
    rep(i, m) {
        ll u, v;
        cin >> u >> v;
        u--; v--;
        g[u].push_back(v);
        g[v].push_back(u);
    }
    ll k;
    cin >> k;
    uset<ll> iwai;
    rep(i, k) {
        ll a;
        cin >> a;
        a--;
        iwai.insert(a);
    }
    vvl dist(n, vl(5, -1));
    queue<P<ll, ll>> que;
    dist[0][0] = 0;
    que.push({0, 0});
    while (!que.empty()) {
        auto [v, iwi] = que.front();
        que.pop();
        foreach(nv, g[v]) {
            ll next_iwi = iwi;
            if (iwai.count(nv)) {
                next_iwi++;
            } else {
                next_iwi = 0;
            }
            if (next_iwi > 4) continue;
            if (dist[nv][next_iwi] != -1) continue;
            dist[nv][next_iwi] = dist[v][iwi] + 1;
            que.push({nv, next_iwi});
        }
    }
    cout << dist[n - 1][0] << "\n";
    return 0;
}