#include <bits/stdc++.h>
#define rep(i,n) for(int i = 0; i < (int)(n); i++)
#define rrep(ri,n) for(int ri = (int)(n-1); ri >= 0; ri--)
#define rep2(i,x,n) for(int i = (int)(x); i < (int)(n); i++)
#define rrep2(ri,x,n) for(int ri = (int)(n-1); ri >= (int)(x); ri--)
#define repit(itr,x) for(auto itr = x.begin(); itr != x.end(); itr++)
#define rrepit(ritr,x) for(auto ritr = x.rbegin(); ritr != x.rend(); ritr++)
#define ALL(x) x.begin(), x.end()
using ll = long long;
using namespace std;

int main() {
  int n, m;
  cin >> n >> m;
  vector<pair<int, int>> a(n);
  vector<int> aa(n);
  rep(i, n) {
    int in;
    cin >> in;
    a.at(i) = {in, i};
    aa.at(i) = in;
  }
  vector<vector<int>> gr(n, vector<int>());
  rep(i, m){
    int a, b;
    cin >> a >> b;
    a--; b--;
    gr.at(a).push_back(b);
    gr.at(b).push_back(a);
  }
  int k;
  cin >> k;
  vector<int> co(n, 0);
  rep(i, k) {
    int in;
    cin >> in;
    in--;
    co.at(in)++;
  }
  sort(ALL(a));
  vector<int> ans;
  for(auto [c, now] : a) {
    if(co.at(now) % 2 == 0) continue;
    ans.push_back(now);
    for(auto nx : gr.at(now)) {
      if(aa.at(nx) <= c) continue;
      co.at(nx)++;
    }
  }
  cout << ans.size() << endl;
  for(auto i : ans) {
    cout << i+1 << endl;
  }
  return 0;
}