#include <bits/stdc++.h>
using namespace std;
typedef long long int ll;
typedef pair<ll,ll> P;
typedef vector<ll> VI;
typedef vector<VI> VVI;
#define REP(i,n) for(int i=0;i<(n);i++)
#define ALL(v) v.begin(),v.end()
constexpr ll MOD=998244353;
constexpr ll INF=2e18;

int main(){
    int n, m; cin >> n >> m;
    VI a(n); vector<P> p(n);
    REP(i,n){
        cin >> a[i];
        p[i]={a[i],i};
    }
    sort(ALL(p));
    VVI g(110000);
    int u, v;
    REP(i,m){
        cin >> u >> v;
        u--, v--;
        g[u].push_back(v);
        g[v].push_back(u);
    }
    VI f(n,0);
    int k; cin >> k;
    int b;
    REP(i,k){
        cin >> b;
        f[b-1]=1;
    }
    int z=0; VI ans;
    REP(i,n){
        if(f[p[i].second]){
            z++;
            ans.push_back(p[i].second+1);
            for(auto to:g[p[i].second]){
                if(p[i].first<a[to])
                    f[to]=!f[to];
            }
        }
    }
    cout << z << endl;
    for(auto i:ans)
        cout << i << endl;
    return 0;
}