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

#define rep(i, n) for (int i = 0; i < (int)(n); i++)

int main()
{
    int N, M;
    cin >> N >> M;
    vector<vector<int>> edges(N);
    rep(i, M)
    {
        int u, v;
        cin >> u >> v;
        u--, v--;
        edges[u].push_back(v), edges[v].push_back(u);
    }

    int K;
    cin >> K;
    vector<bool> is_iwai(N, false);
    rep(i, K)
    {
        int A;
        cin >> A;
        is_iwai[A - 1] = true;
    }

    const int INF = INT32_MAX;

    // dists[i][j] := 岩井星人に連続でj回会ったうえで頂点iに到達するまでの最短距離
    vector<vector<int>> dists(N, vector<int>(5, INF));

    queue<pair<int, int>> qu;
    qu.push({0, 0});
    dists[0][0] = 0;

    while (qu.size())
    {
        auto [now, iwai_cnt] = qu.front();
        qu.pop();

        for (int next : edges[now])
        {
            int next_iwai_cnt = is_iwai[next] ? iwai_cnt + 1 : 0;

            // 次の移動で岩井星人に連続5回会う
            if (5 <= next_iwai_cnt)
            {
                continue;
            }

            // 最短距離を更新しない移動
            if (dists[next][next_iwai_cnt] <= dists[now][iwai_cnt] + 1)
            {
                continue;
            }

            dists[next][next_iwai_cnt] = dists[now][iwai_cnt] + 1;
            qu.push({next, next_iwai_cnt});
        }
    }

    int ans = dists[N - 1][0];
    if (ans == INF)
    {
        cout << -1 << endl;
    }
    else
    {
        cout << ans << endl;
    }

    return 0;
}