#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
istream &operator>>(istream &is, modint &a) { long long v; is >> v; a = v; return is; }
ostream &operator<<(ostream &os, const modint &a) { return os << a.val(); }
istream &operator>>(istream &is, modint998244353 &a) { long long v; is >> v; a = v; return is; }
ostream &operator<<(ostream &os, const modint998244353 &a) { return os << a.val(); }
istream &operator>>(istream &is, modint1000000007 &a) { long long v; is >> v; a = v; return is; }
ostream &operator<<(ostream &os, const modint1000000007 &a) { return os << a.val(); } 

typedef long long ll;
typedef vector<vector<int>> Graph;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
#define FOR(i,l,r) for (int i = l;i < (int)(r); i++)
#define rep(i,n) for (int i = 0;i < (int)(n); i++)
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define my_sort(x) sort(x.begin(), x.end())
#define my_max(x) *max_element(all(x))
#define my_min(x) *min_element(all(x))
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }
const int INF = (1<<30) - 1;
const ll LINF = (1LL<<62) - 1;
const int MOD = 998244353;
const int MOD2 = 1e9+7;
const double PI = acos(-1);
vector<int> di = {1,0,-1,0};
vector<int> dj = {0,1,0,-1};

#ifdef LOCAL
#  include <debug_print.hpp>
#  define debug(...) debug_print::multi_print(#__VA_ARGS__, __VA_ARGS__)
#else
#  define debug(...) (static_cast<void>(0))
#endif

int main(){
    cin.tie(0);
    ios_base::sync_with_stdio(false);

    int N, M; cin >> N >> M;

    Graph g(N);
    rep(_, M){
        int U, V;
        cin >> U >> V;
        g[U - 1].push_back(V - 1);
        g[V - 1].push_back(U - 1);
    }

    int K; cin >> K;
    vector<int> f(N);
    rep(_, K){
        int A; 
        cin >> A;
        f[A - 1] = 1;
    }

    const int C = 5;
    vector dist(C, vector<int>(N, INF));
    dist[0][0] = 0;

    queue<pii> Q;
    Q.push({0, 0});
    while(!Q.empty()){
        auto [c, now] = Q.front();
        Q.pop();

        if(now == N - 1){
            cout << dist[c][now] << endl;
            return 0;
        }

        for(auto nxt : g[now]){
            int nc = f[nxt] ? c + f[nxt] : 0;
            if(nc == C) continue;
            if(dist[nc][nxt] != INF) continue;

            dist[nc][nxt] = dist[c][now] + 1;
            Q.push({nc, nxt});
        }
    }

    cout << -1 << endl;
}