#include <deque>
#include <vector>
#include <cassert>
#include <algorithm>
#include <numeric>
#include <iostream>
using namespace std;


// Find existence of 213 relative permutation in n lg n time.
bool solve(){
	int n; cin >> n;
	deque<pair<int, int>> xy(n), yx(n); // map one coord to the other coord
	for(int x = 0; x < n; ++x){
		int y; cin >> y;
		xy[x] = {x, y};
		yx[x] = {y, x};
	}
	sort(begin(xy), end(xy));
	sort(begin(yx), end(yx));

	// Repeatedly drop points:
	// - bottom left
	// - top left
	// - bottom right
	while(!xy.empty()){
		if(xy.front().second == yx.front().first){
			xy.pop_front();
			yx.pop_front();
			continue;
		}
		if(xy.front().second == yx.back().first){
			xy.pop_front();
			yx.pop_back();
			continue;
		}
		if(xy.back().second == yx.front().first){
			xy.pop_back();
			yx.pop_front();
			continue;
		}
		break;
	}
	
	// If there are >= 3 points left: success!
	assert(xy.size() == yx.size());
	return xy.size() >= 3;
}

int main(){
	int ts; cin >> ts;
	vector<int> ans;
	for(int t = 1; t <= ts; ++t)
		if(solve()) ans.push_back(t);
	cout << ans.size() << endl;
	for(auto x : ans) cout << x << endl;
}