#include <bits/stdc++.h>
using namespace std;
using lint = long long int;
using P = pair<int, int>;
using PL = pair<lint, lint>;
#define FOR(i, begin, end) for(int i=(begin),i##_end_=(end);i<i##_end_;i++)
#define IFOR(i, begin, end) for(int i=(end)-1,i##_begin_=(begin);i>=i##_begin_;i--)
#define REP(i, n) FOR(i,0,n)
#define IREP(i, n) IFOR(i,0,n)
#define ALL(a)  (a).begin(),(a).end()
constexpr int MOD = 1000000007;
constexpr lint B1 = 1532834020;
constexpr lint M1 = 2147482409;
constexpr lint B2 = 1388622299;
constexpr lint M2 = 2147478017;
constexpr int INF = 2147483647;
void yes(bool expr) {cout << (expr ? "YES" : "NO") << "\n";}
template<class T>void chmax(T &a, const T &b) { if (a<b) a=b; }
template<class T>void chmin(T &a, const T &b) { if (b<a) a=b; }
struct Node;
vector<Node> V;
vector<int> ans;
struct Node {
  int idx, A;
  bool light = false;
  vector<int> nbr;
  void solve() {
    if(light) {
      ans.push_back(idx+1);
      for(int x : nbr) if(A < V[x].A) V[x].light = !V[x].light;
    }
  };
};
int main()
{
  ios::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  int N, M;
  cin >> N >> M;
  V = vector<Node>(N);
  vector<P> pa(N);
  REP(i, N) {
    V[i].idx = i;
    cin >> V[i].A;
    pa[i] = P(V[i].A, i);
  }
  sort(ALL(pa));
  REP(i, M) {
    int u, v;
    cin >> u >> v;
    u--; v--;
    V[u].nbr.push_back(v);
    V[v].nbr.push_back(u);
  }
  int K;
  cin >> K;
  REP(i, K) {
    int B;
    cin >> B;
    B--;
    V[B].light = true;
  }
  REP(i, N) V[pa[i].second].solve();
  cout << ans.size() << "\n";
  REP(i, ans.size()) cout << ans[i] << "\n";
}