#include <bits/stdc++.h>
using namespace std;
#define int long long
signed main() {
    int tt; cin >> tt;
    while (tt--) {
        int n; cin >> n;
        vector<pair<int, int>> a(n + 1);
        for (int i = 1; i <= n; i++) {
            cin >> a[i].first;
            a[i].second = i;
        }
        int p, q; cin >> p >> q;
        int r = 1;
        int sum = 0;
        int mx = 0;
        sort(a.begin() + 1, a.begin() + 1 + n);
        for (int i = 1; i <= n; i++) {
            r = max(r, i + 1);
            sum += a[i].first;
            while (r <= n && a[r].first * q * (r - i + 1) <= (a[r].first + sum) * p) {
                sum += a[r].first;
                r++;
            }
            mx = max(mx, r - i);
            sum -= a[i].first;
        }
        // cout << "mx = " << mx << '\n';
        sum = 0;
        for (int i = 2; i <= mx; i++) {
            sum += a[i].first;
        }
        vector<int> ans;
        vector<int> vis(n + 2);
        for (int i = mx; i <= n; i++) {
            int l = 1;
            int r = i - mx + 1;
            while (l < r) {
                int mid = (l + r) >> 1;
                if (a[i].first * q * mx <= (sum + a[mid].first) * p) {
                    r = mid;
                }
                else {
                    l = mid + 1;
                }
            }
            if (a[i].first * q * mx <= (sum + a[l].first) * p) {
                vis[l]++;
                vis[i + 1]--;
            }
            if (i == n) break;
            sum -= a[i - mx + 2].first;
            sum += a[i + 1].first;
        }
        int fl = 0;
        for (int i = 1; i <= n; i++) {
            fl += vis[i];
            if (fl == 0) {
                ans.push_back(a[i].second);
            }
        }
        sort(ans.begin(), ans.end());
        cout << ans.size() << '\n';
        for (int i = 0; i < ans.size(); i++) {
            cout << ans[i] << ' ';
        }
        cout << '\n';
    }
    return 0;
}
/*
1
6
1 2 3 4 1000 10000
4 3
*/