#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
using namespace std;
using ll=long long;
using ull=unsigned long long;
#define rep(i,n) for(int i=0; i<(n); i++)

int N,M;
vector<vector<int>> E;
vector<int> A;
int K;
vector<int> X;

int main(){
  scanf("%d%d",&N,&M);
  A.resize(N);
  rep(i,N) scanf("%d",&A[i]);
  E.resize(N);
  rep(i,M){
    int u,v; scanf("%d%d",&u,&v); u--; v--;
    E[u].push_back(v);
    E[v].push_back(u);
  }
  scanf("%d",&K);
  X.assign(N,0);
  rep(i,N){ int b; scanf("%d",&b); b--; X[b]=1; }
  
  vector<pair<int,int>> Ord;
  rep(i,N) Ord.push_back({A[i],i});
  sort(Ord.begin(),Ord.end());

  vector<int> ans;
  rep(i,N){
    int p = Ord[i].second;
    if(X[p]==0) continue;
    ans.push_back(p);
    X[p] ^= 1;
    for(int e:E[p]) if(A[e]>A[p]) X[e] ^= 1;
  }

  printf("%d\n",(int)ans.size());
  for(int a:ans) printf("%d\n",a+1);
  return 0;
}