#include<bits/stdc++.h>
using namespace std;
#define rep(i,n) for(int i=0;i<n;++i)

int main(){
	int n,m;
	cin>>n>>m;
	vector<vector<int>> es(n);
	rep(i,m) {
		int a,b;
		cin>>a>>b;
		--a;--b;
		es[a].emplace_back(b);
		es[b].emplace_back(a);
	}
	int k;
	cin>>k;
	vector<int> ng(n);
	rep(i,k) {
		int a;
		cin>>a;--a;
		ng[a]=1;
	}
	const int inf=1e9;
	const int p=5;
	vector<vector<int>> d(n,vector<int>(p,inf));
	using T=tuple<int,int,int>;
	priority_queue<T,vector<T>,greater<T>> q;
	q.emplace(0,0,0);
	d[0][0]=0;
	while(q.size()){
		auto [x,i,j]=q.top();q.pop();
		if(d[i][j]!=x) continue;
		for(auto to:es[i]) {
			int nj=j;
			if(ng[to]) nj++;
			else nj=0;
			if(nj==p) continue;
			if(d[i][j]+1<d[to][nj]){
				d[to][nj]=d[i][j]+1;
				q.emplace(d[to][nj],to,nj);
			}
		}
	}
	int ans =*min_element(d.back().begin(),d.back().end());
	if(ans==inf)ans=-1;
	cout<<ans<<endl;
	
}