#include <bits/stdc++.h>
using namespace std;
int main()
{
    int N, M;
    cin >> N >> M;
    int U, V;
    vector<vector<int>> g(N);
    for (int i = 0; i < M; ++i)
    {
        cin >> U >> V;
        U--, V--;
        g[U].push_back(V);
        g[V].push_back(U);
    }
    int K;
    cin >> K;
    int A;
    vector<bool> Y(N, false);
    for (int i = 0; i < K; ++i)
    {
        cin >> A;
        A--;
        Y[A] = true;
    }
    vector<vector<int>> len(N, vector<int>(5, -1));
    len[0][0] = 0;
    queue<pair<int, int>> que;
    que.emplace(0, 0);
    while (que.size())
    {
        int tmp = que.front().first, cnt = que.front().second;
        que.pop();
        for (auto x : g[tmp])
        {
            if (Y[x])
            {
                if (cnt == 4)
                    continue;
                if (len[x][cnt + 1] != -1)
                    continue;
                len[x][cnt + 1] = len[tmp][cnt] + 1;
                que.emplace(x, cnt + 1);
            }
            else
            {
                if (len[x][0] != -1)
                    continue;
                len[x][0] = len[tmp][cnt] + 1;
                que.emplace(x, 0);
            }
        }
    }
    cout << len[N - 1][0] << endl;
    return 0;
}