#include <bits/stdc++.h>
using namespace std;
int main(){
  int N, M;
  cin >> N >> M;
  vector<int> A(N);
  for (int i = 0; i < N; i++){
    cin >> A[i];
  }
  vector<vector<int>> E(N);
  for (int i = 0; i < M; i++){
    int u, v;
    cin >> u >> v;
    u--;
    v--;
    E[u].push_back(v);
    E[v].push_back(u);
  }
  int K;
  cin >> K;
  vector<int> B(K);
  for (int i = 0; i < K; i++){
    cin >> B[i];
    B[i]--;
  }
  vector<pair<int, int>> P(N);
  for (int i = 0; i < N; i++){
    P[i] = make_pair(A[i], i);
  }
  sort(P.begin(), P.end());
  vector<int> id(N);
  for (int i = 0; i < N; i++){
    id[i] = P[i].second;
  }
  vector<bool> c(N, false);
  for (int i = 0; i < K; i++){
    c[B[i]] = true;
  }
  vector<int> x;
  for (int i = 0; i < N; i++){
    if (c[id[i]]){
      c[id[i]] = false;
      x.push_back(id[i]);
      for (int j : E[id[i]]){
        if (A[id[i]] < A[j]){
          c[j] = !c[j];
        }
      }
    }
  }
  int Z = x.size();
  cout << Z << endl;
  for (int i = 0; i < Z; i++){
    cout << x[i] + 1 << endl;
  }
}