#include <bits/stdc++.h>
using namespace std;
using ll=long long;
int main(){
	int n,m;
	cin>>n>>m;
	vector<vector<int>> graph(n);
	for(int i=0;i<m;i++){
		int u,v;
		cin>>u>>v;
		u--;v--;
		graph[u].push_back(v);
		graph[v].push_back(u);
	}
	int k;
	cin>>k;
	vector<bool> a(n);
	for(int i=0;i<k;i++){
		int t;
		cin>>t;
		//cout<<t<<endl;
		a[t-1]=true;
	}
	queue<pair<int,int>> que;
	que.push(make_pair(0,0));
	vector<vector<int>> seen(n,vector<int>(5,-1));
	seen[0][0]=0;
	int ans=1e9;
	while(!que.empty()){
		auto[v,x]=que.front();
		//cout<<"v:"<<v<<endl;
		que.pop();
		for(int u:graph[v]){
			//cout<<"u:"<<u<<endl;
			int y=x;
			if(a[u])y++;
			else y=0;
			//cout<<y<<endl;
			if(y==5||seen[u][y]!=-1)continue;
			seen[u][y]=seen[v][x]+1;
			if(u==n-1)ans=min(ans,seen[u][y]);
			que.push(make_pair(u,y));
		}
	}
	if(ans<1e9)cout<<ans<<endl;
	else cout<<-1<<endl;
}