#include <bits/stdc++.h>
//#include <atcoder/all>
using namespace std;
//using namespace atcoder;
//using mint = modint1000000007;
//const int mod = 1000000007;
//using mint = modint998244353;
//const int mod = 998244353;
const int INF = 1e9;
//const long long LINF = 1e18;
#define rep(i, n) for (int i = 0; i < (n); ++i)
#define rep2(i,l,r)for(int i=(l);i<(r);++i)
#define rrep(i, n) for (int i = (n) - 1; i >= 0; --i)
#define rrep2(i,l,r)for(int i=(r) - 1;i>=(l);--i)
#define all(x) (x).begin(),(x).end()
#define allR(x) (x).rbegin(),(x).rend()
#define P pair<int,int>
template<typename A, typename B> inline bool chmax(A & a, const B & b) { if (a < b) { a = b; return true; } return false; }
template<typename A, typename B> inline bool chmin(A & a, const B & b) { if (a > b) { a = b; return true; } return false; }

int main() {
	std::ios::sync_with_stdio(false);
	std::cin.tie(nullptr);
	int n, m; cin >> n >> m;
	vector to(n, vector<int>());
	rep(i, m) {
		int u, v; cin >> u >> v;
		u--, v--;
		to[u].push_back(v);
		to[v].push_back(u);
	}
	vector<bool>has(n);
	int k; cin >> k;
	rep(i, k) {
		int a; cin >> a;
		has[a - 1] = true;
	}
	vector dp(5, vector<int>(n, INF));
	dp[0][0] = 0;
	queue<P>que;
	que.push({ 0,0 });
	while (!que.empty()) {
		auto[c, v] = que.front();
		que.pop();
		for (auto nv : to[v]) {
			int nc = has[nv] ? c + 1 : 0;
			if (nc == 5)continue;
			int nval = dp[c][v] + 1;
			if (chmin(dp[nc][nv], nval)) {
				que.push({ nc,nv });
			}
		}
	}
	int ans = INF;
	rep(i, 5)chmin(ans, dp[i][n - 1]);
	if (ans == INF)ans = -1;
	cout << ans << endl;
	return 0;
}