#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define rep(i, s, t) for (ll i = s; i < (ll)(t); i++)
#define all(x) begin(x), end(x)

template <class T> bool chmin(T& x, T y) {
	return x > y ? (x = y, true) : false;
}
template <class T> bool chmax(T& x, T y) {
	return x < y ? (x = y, true) : false;
}

struct io_setup {
	io_setup() {
		ios::sync_with_stdio(false);
		cin.tie(nullptr);
		cout << fixed << setprecision(15);
	}
} io_setup;

void solve() {
	int n, m;
	cin >> n >> m;
	vector<vector<int>> g(n);
	rep(i, 0, m) {
		int u, v;
		cin >> u >> v;
		u--, v--;
		g[u].push_back(v);
		g[v].push_back(u);
	}
	int k;
	cin >> k;
	vector<int> wall(n, 0);
	rep(i, 0, k) {
		int a;
		cin >> a;
		a--;
		wall[a] = 1;
	}
	vector<vector<int>> dist(5, vector<int>(n, -1));
	dist[0][0] = 0;
	vector<array<int, 2>> vp = {{0, 0}};
	rep(i, 0, vp.size()) {
		auto [d, nw] = vp[i];
		if (nw == n - 1) {
			cout << dist[d][nw] << "\n";
			return;
		}
		for (int nx : g[nw]) {
			int nd = d;
			if (wall[nx]) nd++;
			else nd = 0;
			if (nd >= 5) continue;
			if (dist[nd][nx] != -1) continue;
			dist[nd][nx] = dist[d][nw] + 1;
			vp.push_back({nd, nx});
		}
	}
	cout << "-1\n";
}

int main() {
	int t = 1;
	// cin >> t;
	while (t--) solve();
}