#include <bits/stdc++.h>

using loint = long long;
using db = double;

void solve() {
    
    int n;
    std::cin >> n;
    std::vector<int> a(n + 1);
    for (int i = 1; i <= n; i ++) {
        std::cin >> a[i];
    }

    int cnt = 0, cur = 1;
    std::vector<int> vis(n + 1);
    while (!vis[cur]) {
        vis[cur] ++;
        cnt ++;
        cur = a[cur];
    }

    if (cnt != n) {
        std::cout << cnt << '\n';
        for (int i = 1; i <= n; i ++) {
            if (vis[i]) {
                std::cout << i << ' ';
            }
        }
        std::cout << '\n';
        return;
    }

    int ans = 0, p = 1;
    for (int i = 1; i <= n; i ++) {
        int l = std::min(i, a[i]), r = std::max(i, a[i]);
        int len = r - l + 1;
        if (n - len > ans) {
            ans = n - len;
            p = i;
        }
    }

    std::cout << 1 << '\n';
    std::cout << p << '\n';
}

int main() {

    std::ios::sync_with_stdio(false);
    std::cin.tie(0);
    std::cout.tie(0);

    int _;
    _ = 1;
    std::cin >> _;
    while(_--)
        solve();

    return 0;
}