// 2025 9/6
// 2025 9/6

#include <bits/stdc++.h>
using namespace std;
#define int long long
const int mod = 998244353;
template <class T>
void out(vector<vector<T>> v)
{
    for (int i = 0; i < (int)v.size(); i++)
        for (int j = 0; j < (int)v.at(i).size(); j++)
        {
            cout << v.at(i).at(j) << " ";
            if (j == (int)v.at(i).size() - 1)
                cout << endl;
        }
}
template <class T>
void out2(vector<vector<vector<T>>> v)
{
    cout << "-----------------" << endl;
    for (int i = 0; i < (int)v.size(); i++)
    {
        cout << "i:" << i << endl;
        for (int j = 0; j < (int)v.at(i).size(); j++)
            for (int k = 0; k < (int)v.at(i).at(j).size(); k++)
            {
                cout << v.at(i).at(j).at(k) << " ";
                if (k == (int)v.at(i).at(j).size() - 1)
                    cout << endl;
            }
        cout << "-----------------" << endl;
    }
}
template <class T>
void out3(vector<vector<vector<T>>> v)
{
    cout << "-----------------" << endl;
    for (int k = 0; k < (int)v.at(0).at(0).size(); k++)
    {
        cout << "k:" << k << endl;
        for (int i = 0; i < (int)v.size(); i++)
        {
            for (int j = 0; j < (int)v.at(i).size(); j++)
            {
                cout << v.at(i).at(j).at(k) << " ";
                if (j == v.at(i).size() - 1)
                    cout << endl;
            }
        }
        cout << "-----------------" << endl;
    }
}
template <class T>
bool chmax(T &a, T b)
{
    if (a < b)
    {
        a = b;
        return true;
    }
    return false;
}
template <class T>
bool chmin(T &a, T b)
{
    if (a > b)
    {
        a = b;
        return true;
    }
    return false;
}
int power(int x, int n, int mod)
{
    int ret = 1;
    while (n > 0)
    {
        if (n & 1)
        {
            ret *= x;

            if (mod > 0)
                ret %= mod;
        }

        x *= x;
        if (mod > 0)
            x %= mod;

        n >>= 1;
    }
    return ret;
}

signed main(void)
{
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    int n, m;
    cin >> n >> m;

    vector<vector<int>> g(n);
    for (int i = 0; i < m; i++)
    {
        int u, v;
        cin >> u >> v;
        u--;
        v--;

        g.at(u).push_back(v);
        g.at(v).push_back(u);
    }

    int k;
    cin >> k;
    vector<int> is(n, 0);
    for (int i = 0; i < k; i++)
    {
        int a;
        cin >> a;
        a--;
        is.at(a) = 1;
    }

    vector<vector<int>> dist(n, vector<int>(5, -1)); // i番目の頂点で、岩井星人に連続してj回あっている場合の最短経路
    queue<pair<int, int>> que;                       // (頂点番号, 連続して岩井星人に会っている回数)

    dist.at(0).at(0) = 0;
    que.push({0, 0});

    while (!que.empty())
    {
        pair p = que.front();
        que.pop();

        for (int u : g.at(p.first))
        {
            if (is.at(u) == 1)
            {
                if (p.second + 1 < 5 && dist.at(u).at(p.second + 1) == -1)
                {
                    dist.at(u).at(p.second + 1) = dist.at(p.first).at(p.second) + 1;
                    que.push({u, p.second + 1});
                }
            }
            else
            {
                if (dist.at(u).at(0) == -1)
                {
                    dist.at(u).at(0) = dist.at(p.first).at(p.second) + 1;
                    que.push({u, 0});
                }
            }
        }
    }
    
    int ans = INT_MAX;
    for (int i = 0; i < 5; i++)
    {
        if (dist.at(n - 1).at(i) == -1)
            continue;

        chmin(ans, dist.at(n - 1).at(i));
    }

    if (ans == INT_MAX)
        cout << -1 << endl;
    else
        cout << ans << endl;
}