#include <bits/stdc++.h>
#define rep(i,n) for(int i = 0; i < (n); ++i)
#define srep(i,s,t) for (int i = s; i < t; ++i)
#define drep(i,n) for(int i = (n)-1; i >= 0; --i)
using namespace std;
typedef long long int ll;
typedef pair<int,int> P;
#define yn {puts("YES");}else{puts("NO");}
#define MAX_N 200005

vector<int> G[MAX_N];

int main() {
    int n, m;
    cin >> n >> m;
    int a[n] = {};
    rep(i,n) cin >> a[i];
    rep(i,m){
        int u, v;
        cin >> u >> v;
        u--; v--;
        G[u].push_back(v);
        G[v].push_back(u);
    }
    vector<P> v;
    rep(i,n){
        v.push_back(P(a[i],i));
    }
    sort(v.begin(), v.end());
    int f[n] = {};
    int k; cin >> k;
    rep(i,k){
        int b; cin >> b;
        b--;
        f[b] = 1;
    }
    vector<int> ans;

    rep(i,n){
        int x = v[i].second;
        if(f[x] == 1){
            ans.push_back(x+1);
            f[x] = 0;
            rep(j,G[x].size()){
                int y = G[x][j];
                if(a[x] < a[y]) f[y] = 1 - f[y];
            }
        }
    }

    cout << ans.size() << endl;
    rep(i,ans.size()){
        cout << ans[i] << endl;
    }
    return 0;
}