#include<bits/stdc++.h>
using namespace std;
#define OVERLOAD_REP(_1, _2, _3, name, ...) name
#define REP1(i, n) for (auto i = std::decay_t<decltype(n)>{}; (i) != (n); ++(i))
#define REP2(i, l, r) for (auto i = (l); (i) != (r); ++(i))
#define rep(...) OVERLOAD_REP(__VA_ARGS__, REP2, REP1)(__VA_ARGS__)
#define REP(i, l, r) rep(i, l, r+1)
#define all(x) (x).begin(),(x).end()
#define rall(x) (x).rbegin(),(x).rend()
using ll = long long;
using ld = long double;
using P = pair<ll,ll>;
struct Edge {
  int to; ll w;
};
using Graph = vector<vector<int> >;
//using Graph = vector<vector<Edge> >;
const ll INF = 2e18;
//const int INF = 2e9;
template<class T> using vc = vector<T>;
template<class T> using vv = vector<vector<T> >;
template<class T> using vvv = vector<vector<vector<T> > >;
template<class T> using pq = priority_queue<T>;
template<class T> using pq_g = priority_queue<T, vc<T>, greater<T> >;
template<class T> istream& operator>>(istream& i, vc<T>& v) { rep(j, 0, v.size()) i>>v[j]; return i; }
template<class T> ostream& operator<<(ostream& o, vc<T>& v) { rep(j, 0, v.size()) o<<v[j]<<" "; return o; }
template<class T> bool chmin(T& a, T b) {
  if(a > b) {
      a = b;
      return true;
  }
  return false;
}
template<class T> bool chmax(T& a, T b) {
  if(a < b) {
      a = b;
      return true;
  }
  return false;
}

vc<int> com;
vc<bool> seen;
void rec(const Graph& G, vc<bool>& b, int v) {
  if(seen[v]) return;
  seen[v] = true;
  if(b[v]) com.push_back(v);
  for(int u : G[v]) b[u] = !b[u];
  for(int u : G[v]) {
    rec(G, b, u);
  }
}
int main() {
  // 高速化
  ios::sync_with_stdio(false);
  cin.tie(nullptr);

  // 小数点の出力桁数を指定
  cout << fixed << setprecision(10);
  // メイン
  int N, M;
  cin >> N >> M;
  vc<int> A(N);
  cin >> A;
  Graph G(N);
  vc<int> cnt(N, 0);
  rep(i, 0, M) {
    int u, v;
    cin >> u >> v;
    u--, v--;
    if(A[u] < A[v]) G[u].push_back(v), cnt[v]++;
    if(A[v] < A[u]) G[v].push_back(u), cnt[u]++;
  }

  vc<bool> b(N, false);
  int K; cin >> K;
  rep(i, 0, K) {
    int B; cin >> B; B--;
    b[B] = true;
  }

  seen.assign(N, false);
  rep(i, 0, N) {
    rec(G, b, i);
  }

  cout << com.size() << endl;
  rep(i, 0, com.size()) cout << com[i]+1 << endl;

  return 0;
}