#include <bits/stdc++.h>
#define ll long long
 
using namespace std;
 
int main(){
    ll t;
	cin >> t;
	while(t--){
	    ll n;
		cin >> n;
		
		ll a,sum=0;
		
		map <ll, vector <ll> > m;
 
		ll i;
		ll ans=0;
		for(i=0;i<n;i++){
			cin >> a;
			if(a%n == 0){
				ans = a;
				break;
			}
 
			sum +=a;
			sum %=n;
			m[sum].push_back(i+1);
		}
 
		if(i != n){
			cout << 1 << endl << i+1 << endl;
			continue;
		}
		
// 		for(auto i : m){
// 		    cout << i.first <<" -> ";
		    
// 		    for(auto k : i.second){
// 		        cout << k << " ";
// 		    }
		    
// 		    cout << endl;
// 		}
	
 
	//1,2,3,4,5....N
	for(auto i : m){
		if(i.first == 0){
		    
			cout << i.second[0] << endl;
			for(ll k=1;k<=i.second[0];k++){
			    cout << k << " ";
			}
			cout << endl;
			break;
		}
		else{
			if(i.second.size() >= 2){
				cout << i.second[1] - i.second[0] << endl;
 
				for(ll k=i.second[0]+1;k<=i.second[1];k++){
					cout << k << " ";
				}
 
				cout << endl;
				break;
			}
		}
	}
 
}
 
 
	return 0;
}