#include <bits/stdc++.h>

#include <atcoder/fenwicktree.hpp>
#include <atcoder/segtree.hpp>
#include <atcoder/modint.hpp>
#include <atcoder/dsu.hpp>
#include <atcoder/lazysegtree.hpp>

using namespace atcoder;
using namespace std;
using ll = long long;
using ull = unsigned long long;
template <class T>
using max_heap = priority_queue<T>;
template <class T>
using min_heap = priority_queue<T, vector<T>, greater<>>;
ll ll_min = numeric_limits<ll>::min();
ll ll_max = numeric_limits<ll>::max();
ll ALPHABET_N = 26;
using mint = modint998244353;
#define rep(i, n) for (ll i = (ll)0; i < (ll)n; i++)
#define rep_(i, k, n) for (ll i = (ll)k; i < (ll)n; i++)
#define all(a) a.begin(), a.end()

int main()
{
	ios::sync_with_stdio(false);
	cin.tie(0);
	ll n, m;
	cin >> n >> m;
	vector<vector<ll>> g(n);
	rep(i, m)
	{
		ll a, b;
		cin >> a >> b;
		a--;
		b--;
		g[a].push_back(b);
		g[b].push_back(a);
	}
	ll k;
	cin >> k;
	set<ll> st;
	rep(i, k)
	{
		ll a;
		cin >> a;
		a--;
		st.insert(a);
	}
	vector<vector<ll>> min_cost(n, vector<ll>(5, ll_max));
	min_cost[0][0] = 0;
	queue<tuple<ll, ll, ll>> que;
	que.push({0, 0, 0});
	while (!que.empty())
	{
		auto [v, c, cdist] = que.front();
		que.pop();
		for (auto nv : g[v])
		{
			ll nc;
			if (st.count(nv))
			{
				nc = c + 1;
			}
			else
			{
				nc = 0;
			}
			if (nc > 4)
				continue;
			ll ncdist = cdist + 1;
			if (min_cost[nv][nc] > ncdist)
			{
				min_cost[nv][nc] = ncdist;
				que.push({nv, nc, ncdist});
			}
		}
	}
	ll ans = ll_max;
	rep(i, 5)
	{
		ans = min(ans, min_cost[n - 1][i]);
	}
	if (ans == ll_max)
		ans = -1;
	cout << ans << endl;
	return 0;
}