#include <bits/stdc++.h>

using namespace std;

void fast_io() {
	ios::sync_with_stdio(false);
	std::cin.tie(nullptr);
}

int main() {
	fast_io();
	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[u].push_back(v);
		g[v].push_back(u);
	}
	vector<bool> flg(n);
	int k;
	cin >> k;
	for (int i = 0; i < k; i++) {
		int x;
		cin >> x;
		x--;
		flg[x] = true;
	}
	vector<vector<int>> dist(n, vector<int>(5, -1));
	deque<pair<int, int>> dq;
	dist[0][0] = 0;
	dq.push_back({0, 0});
	while (!dq.empty()) {
		auto [u, c] = dq.front();
		dq.pop_front();
		for (int v : g[u]) {
			int nc = flg[v] ? c + 1 : 0;
			if (nc < 5 && dist[v][nc] == -1) {
				dist[v][nc] = dist[u][c] + 1;
				dq.push_back({v, nc});
			}
		}
	}
	const int INF = 1e9;
	int ans = INF;
	for (int i = 0; i < 5; i++) {
		if (dist[n - 1][i] != -1) {
			ans = min(ans, dist[n - 1][i]);
		}
	}
	if (ans == INF) {
		ans = -1;
	}
	cout << ans << endl;
}