#include <iostream>
#include <algorithm>
#include <map>
#include <set>
#include <queue>
#include <stack>
#include <numeric>
#include <bitset>
#include <cmath>

static const int MOD = 1000000007;
using ll = long long;
using u32 = unsigned;
using u64 = unsigned long long;
using namespace std;

template<class T> constexpr T INF = ::numeric_limits<T>::max() / 32 * 15 + 208;

int main() {
    int n, m;
    cin >> n >> m;
    vector<int> A(n);
    for (auto &&i : A) scanf("%d", &i);
    vector<vector<int>> G(n);
    for (int i = 0; i < m; ++i) {
        int u, v;
        scanf("%d %d", &u, &v);
        u--; v--;
        G[u].emplace_back(v);
        G[v].emplace_back(u);
    }
    auto f = [&](int a, int b){ return A[a] < A[b]; };
    set<int, decltype(f)> s(f);
    int k;
    cin >> k;
    for (int i = 0; i < k; ++i) {
        int x;
        scanf("%d", &x);
        s.emplace(x-1);
    }
    vector<int> ans;
    while(!s.empty()){
        int a = *s.begin();
        ans.emplace_back(a);
        s.erase(a);
        for (auto &&b : G[a]) {
            if(A[a] < A[b]) {
                if(s.count(b)) s.erase(b);
                else s.emplace(b);
            }
        }
    }
    cout << ans.size() << "\n";
    for (auto &&i : ans) {
        cout << i+1 << "\n";
    }
    return 0;
}