#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define ALL(v) v.begin(), v.end()
typedef long long ll;

#include <bits/stdc++.h>
using namespace std;

vector<int> G[100100];
int B[100100];

int main(){
  int n,m;
  cin>>n>>m;
  vector<pair<int,int>> A(n);
  vector<int> AA(n);
  rep(i,n){
    int a;
    cin>>a;
    AA[i]=a;
    A[i]={a,i};
  }
  sort(ALL(A));
  rep(i,m){
    int u,v;
    cin>>u>>v;
    u--,v--;
    G[u].push_back(v);
    G[v].push_back(u);
  }
  int k;
  cin>>k;
  rep(i,k){
    int b;
    cin>>b;
    b--;
    B[b]=1;
  }
  vector<int> C;
  rep(i,n){
    int ta=A[i].first;
    int ti=A[i].second;
    if(B[ti]==1){
      C.push_back(ti+1);
      B[ti]=0;
      for(auto x:G[ti]){
        if(AA[x]>ta) B[x]=1-B[x];
      }
    }
  }
  cout<<(int)C.size()<<endl;
  rep(i,(int)C.size()) cout<<C[i]<<endl;
  
  return 0;
}