#include<bits/stdc++.h>
using namespace std;
#define rep(i,n) for(int i = 0; i < int(n); i++)
#define FOR(i,a,b) for(ll i = a; i < (ll)(b); i++)
#define all(a) (a).begin(),(a).end()
using ll = long long;
using VI = vector<int>;
using P = pair<int,int>;
const long long INF = 1LL << 60;
const int DX[] = {1,0,-1,0};
const int DY[] = {0,1,0,-1};

int main(){
	cin.tie(nullptr);
	ios_base::sync_with_stdio(false);
	
	ll n,m;
	cin >> n >> m;
	vector<vector<ll>> g(n);
	rep(i,m){
		ll u,v; cin >> u >> v; u--; v--;
		g[u].push_back(v);
		g[v].push_back(u);
	}
	
	ll k;
	cin >> k;
	vector<bool> is_iwai(n,0);
	rep(i,k){
		ll a; cin >> a;
		is_iwai[a-1] = true;
	}
	
	vector<vector<ll>> dist(n,vector<ll>(5,1e18));
	queue<pair<ll,ll>> q;
	q.push({0,0});
	dist[0][0] = 0;
	
	while(!q.empty()){
		auto [x,cnt] = q.front();
		q.pop();
		
		for(auto nx : g[x]){
			ll next_cnt = cnt;
			if(is_iwai[nx]) next_cnt++;
			else next_cnt = 0;
			
			if(next_cnt >= 5) continue;
			if(dist[nx][next_cnt] > dist[x][cnt] + 1){
				dist[nx][next_cnt] = dist[x][cnt] + 1;
				q.push({nx,next_cnt});
			}
		}
	}
	
	ll ans = *min_element(all(dist[n-1]));
	if(ans == 1e18) cout << -1 << endl;
	else cout << ans << endl;
	return 0;
}