#include <stdio.h>
#include <bits/stdc++.h>
#include <atcoder/all>
using namespace atcoder;
using mint = modint998244353;
using namespace std;
#define rep(i,n) for (int i = 0; i < (n); ++i)
#define Inf 1000000001

int main(){
	
	int N,M;
	cin>>N>>M;
	
	vector<int> A(N);
	vector<pair<int,int>> P;
	rep(i,N){
		cin>>A[i];
		P.emplace_back(A[i],i);
	}
	
	vector<vector<int>> E(N);
	rep(i,M){
		int u,v;
		cin>>u>>v;
		u--;v--;
		E[u].push_back(v);
		E[v].push_back(u);
	}
	
	vector<int> b(N,0);
	int K;
	cin>>K;
	
	rep(i,K){
		int B;
		cin>>B;
		b[B-1] = 1;
	}
	
	sort(P.begin(),P.end());
	vector<int> ans;
	
	rep(i,P.size()){
		int ind = P[i].second;
		if(b[ind]){
			ans.push_back(ind+1);
			b[ind] ^= 1;
			rep(j,E[ind].size()){
				if(A[ind] < A[E[ind][j]]){
					b[E[ind][j]] ^= 1;
				}
			}
		}
	}
	
	cout<<ans.size()<<endl;
	rep(i,ans.size()){
		cout<<ans[i]<<endl;
	}
	
    return 0;
}