#include <iostream>
#include <vector>
#include <map>
#include <set>
#include <queue>
#include <algorithm>
#include <string>
#include <cmath>
#include <cstdio>
#include <iomanip>
#include <fstream>
#include <cassert>
#include <cstring>
#include <unordered_set>
#include <unordered_map>
#include <numeric>
#include <ctime>
#include <bitset>
#include <random>
#include <complex>
#include <random>
#include <functional>

using namespace std;

void solve() {
    int n;
    cin >> n;
    vector<int> a(n + 1);
    vector<vector<int>> g(n + 1);
    for (int i = 1; i <= n; i++) {
        cin >> a[i];
        g[i].push_back(i - a[i]);
    }
    for (int i = 1; i <= n; i++) {
        if (a[i] == 0) {
            cout << 1 << '\n' << i << '\n';
            return;
        }
    }
    vector<int> used(n + 1);
    pair<int, int> rs = {-1, -1};
    function<void(int)> dfs = [&](int cur) {
        used[cur] = 1;
        for (auto t : g[cur]) {
            if (used[t] == 0) {
                dfs(t);
            }
            if (used[t] == 1) {
                rs = {cur, t};
            }
        }
        used[cur] = 2;
    };
    for (int i = 1; i <= n; i++) {
        if (used[i] == 0) {
            dfs(i);
        }
    }
    swap(rs.first, rs.second);
    fill(used.begin(), used.end(), 0);
    vector<int> p(n + 1);
    function<void(int, int)> dfs2 = [&](int cur, int pr) {
        used[cur] = 1;
        p[cur] = pr;
        for (auto t : g[cur]) {
            if (used[t] == 0) {
                dfs2(t, cur);
            }
        }
        used[cur] = 2;
    };
    dfs2(rs.first, -1);
    assert(used[rs.second]);
    vector<int> v = {rs.first};
    int cur = rs.second;
    while (cur != rs.first) {
        v.push_back(cur);
        cur = p[cur];
    }
    cout << v.size() << '\n';
    for (auto t : v) {
        cout << t << ' ';
    }
    cout << '\n';

}

signed main() {
    ios_base::sync_with_stdio(false);
    cin.tie(0);

    int q;
    cin >> q;
    while (q--) {
        solve();
    }
}