#include <bits/stdc++.h>
using namespace std;
#define rep(i, x, limit) for (long long i = (long long)x; i < (long long)limit; i++)
#define REP(i, x, limit) for (long long i = (long long)x; i <= (long long)limit; i++)
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define el '\n'
#define spa " "
#define Yes cout << "Yes" << el
#define No cout << "No" << el
#define YES cout << "YES" << el
#define NO cout << "NO" << el
#define inp(x) for(auto &i:x)cin>>i
#define eps (1e-10)
#define Equals(a,b) (fabs((a) - (b)) < eps )
#define debug(x) cerr << #x << " = " << x << el
using ll = long long;
using ull = unsigned long long;
using i128 = __int128_t;
using pii = pair<int,int>;
using pll = pair<ll,ll>;
using vi = vector<int>;
using vl = vector<ll>;
using vvl = vector<vector<ll>>;
using vs = vector<string>;
using vb = vector<bool>;
const double pi = 3.141592653589793238;
const int inf = 1073741823;
const ll infl = 1LL << 60;
const string ABC = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
const string abc = "abcdefghijklmnopqrstuvwxyz";
const ll MOD = 998244353;
#include<atcoder/all>
using namespace atcoder;
using mint = modint998244353;
using vm = vector<mint>;

int main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  ll n,m;cin>>n>>m;
  vl A(n);inp(A);
  vvl G(n);
  rep(i,0,m){
    ll u,v;cin>>u>>v;
    u--;v--;
    if(A[u]==A[v])continue;
    if(A[u]>A[v])swap(u,v);
    G[u].push_back(v);
  }
  vector<pll> Ai(n);
  rep(i,0,n){
    Ai[i]={A[i],i};
  }
  sort(all(Ai));
  ll k;cin>>k;
  vl B(k),ans;inp(B);
  vb L(n,false);
  for(auto b:B){
    L[b-1]=true;
  }
  for(auto[x,y]:Ai){
    if(L[y]){
      ans.push_back(y+1);
      for(auto g:G[y]){
        L[g]=1-L[g];
      }
    }
  }
  cout<<ans.size()<<el;
  for(auto aa:ans){
    cout<<aa<<el;
  }
}