#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;
	set<ll> st;
	rep(i,k){
		ll a;
		cin >> a;
		st.insert(a);
	}
	
	vector<vector<ll>> dist(n,vector<ll>(5,1e9));
	queue<pair<ll,pair<ll,ll>>> q;
	q.push({0,{0,0}});
	dist[0][0] = 0;
	
	while(!q.empty()){
		ll x = q.front().first;
		ll cnt = q.front().second.first;
		ll d = q.front().second.second;
		q.pop();
		
		for(auto nx : g[x]){
			ll nc = cnt;
			if(st.count(nx)){
				nc++;
			}
			else nc = 0;
			
			if(nc < 5 && dist[nx][nc] > d+1){
				q.push({nx,{nc,d+1}});
				dist[nx][cnt] = d+1;
			}
		}
	}
	
	ll ans = *min_element(all(dist[n-1]));
	if(ans == 1e9) cout << -1 << endl;
	else cout << ans << endl;
	return 0;
}