#include <bits/stdc++.h>
#define rep(i,n) for(int i=0;i<(int)(n);i++)
#define chmin(x,y) x = min((x),(y))
#define chmax(x,y) x = max((x),(y))
#define popcount(x) __builtin_popcount(x)
using namespace std;
using ll = long long ;
using P = pair<int,int> ;
using pll = pair<long long,long long>;
const int INF = 1e9;
const long long LINF = 1e17;
const int MOD = 1000000007;
//const int MOD = 998244353;
const double PI = 3.14159265358979323846;

int main(){
    int n,m;
    cin >> n >> m;
    vector<int> a(n);
    rep(i,n) cin >> a[i];
    vector<vector<int>> G(n);
    rep(i,m){
        int u,v;
        cin >> u >> v;
        --u;--v;
        G[u].push_back(v);
        G[v].push_back(u);
    }
    int k;
    cin >> k;
    vector<int> on(n,0);
    rep(i,k){
        int b;
        cin >> b;
        --b;
        on[b] = 1;
    }

    vector<int> id(n);
    iota(id.begin(),id.end(),0);
    sort(id.begin(),id.end(),[&](int l,int r){
        return a[l] < a[r];
    });

    int ans = 0;
    vector<int> res;

    for(int _i=0;_i<n;_i++){
        int i = id[_i];
        if(on[i] == 1){
            ++ans;
            on[i] = 0;
            res.push_back(i);
            for(int j:G[i]){
                if(a[j] > a[i]) on[j] = 1 - on[j];
            }
        }
    }
    cout << ans << endl;
    for(int i:res) cout << i+1 << endl;

    return 0;
}