#include <bits/stdc++.h>
using namespace std;

struct iofast_t {
    iofast_t() {
        ios::sync_with_stdio(false);
        cin.tie(nullptr); cout.tie(nullptr);
    }
} iofast;

struct uns_t {} uns;
template <typename Element, typename Head, typename ...Args>
auto vec(Element init, Head arg, Args ...args) {
    if constexpr (sizeof...(Args) == 0) return std::vector(arg, init);
    else return std::vector(arg, vec(init, args...));
}
template <typename Element, typename Head, typename ...Args>
auto vec(uns_t, Head arg, Args ...args) {
    return vec(Element(), arg, args...);
}

template <typename T, typename Compare = less<T>>
T &chmin(T &l, T r, Compare &&f = less<T>()) { return l = min(l, r, f); }
template <typename T, typename Compare = less<T>>
T &chmax(T &l, T r, Compare &&f = less<T>()) { return l = max(l, r, f); }

int main() {
    int n, m; cin >> n >> m;
    auto a = vec<int>(uns, n);
    for (auto &e : a) cin >> e;

    auto g = vec<int>(uns, n, 0);
    for (int i = 0; i < m; ++i) {
        int u, v; cin >> u >> v; --u; --v;

        if (a[u] > a[v]) {
            swap(u, v);
        }

        if (a[u] != a[v]) {
            g[u].push_back(v);
        }
    }

    auto sorted = vec<int>(uns, 0);

    auto vis = vec<bool>(false, n);
    auto dfs = [&](auto &&dfs, int u) -> void {
        if (vis[u]) return;
        vis[u] = true;

        for (auto v : g[u]) {
            dfs(dfs, v);
        }

        sorted.push_back(u);
    };

    for (int i = 0; i < n; ++i) {
        dfs(dfs, i);
    }
    reverse(begin(sorted), end(sorted));

    int k; cin >> k;
    auto s = vec<bool>(false, n);
    for (int i = 0; i < k; ++i) {
        int b; cin >> b; --b;
        s[b] = true;
    }

    auto ans = vec<int>(uns, 0);
    for (auto u : sorted) {
        if (!s[u]) continue;
        ans.push_back(u);

        s[u] = false;
        for (auto v : g[u]) {
            s[v] = !s[v];
        }
    }

    cout << size(ans) << endl;
    for (auto e : ans) {
        cout << e + 1 << endl;
    }
}