/**
 *   @FileName	a.cpp
 *   @Author	kanpurin
 *   @Created	2021.04.16 21:53:14
**/

#include "bits/stdc++.h" 
using namespace std; 
typedef long long ll;

int main() {
    int n,m;cin >> n >> m;
    vector<int> a(n);
    vector<int> idx(n);
    iota(idx.begin(), idx.end(),0);
    for (int i = 0; i < n; i++) {
        cin >> a[i];
    }
    sort(idx.begin(), idx.end(),[&](int x,int y) {
        return a[x] < a[y];
    });
    vector<vector<int>> g(n);
    for (int i = 0; i < m; i++) {
        int u,v;cin >> u >> v;
        u--;v--;
        g[u].push_back(v);
        g[v].push_back(u);
    }
    int k;cin >> k;
    vector<int> b(n,0);
    for (int i = 0; i < k; i++) {
        int t;cin>>t;
        b[--t] = 1;
    }
    vector<int> ans;
    for (int i = 0; i < n; i++) {
        if (b[idx[i]] == 0) continue;
        b[idx[i]] = 0;
        ans.push_back(idx[i]+1);
        for(int v : g[idx[i]]) {
            if (a[v] <= a[idx[i]]) continue;
            b[v] = 1 - b[v];
        }
    }
    
    
    cout << ans.size() << endl;
    for (int i = 0; i < ans.size(); i++) {
        cout << ans[i] << endl;
    }
    return 0;
}