Untitled

#include < bits/stdc++.h >
using namespace std;
 
#define IOS ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
#define endl "\n"
#define int long long

const int N = 2e5 + 5;

int n;
int a[N];

int32_t main()
{
	IOS;
	int t;
	cin >> t;
	while(t--)
	{
		cin >> n;
		vector< int > even, odd;
		for(int i = 1; i <= 2 * n; i++)
		{
			cin >> a[i];
			if(a[i] % 2)
				odd.push_back(i);
			else
				even.push_back(i);
		}
		vector< pair< int, int > > ans;
		for(int i = 0; i + 1 < odd.size(); i += 2)
			ans.push_back({odd[i], odd[i + 1]});
		for(int i = 0; i + 1 < even.size(); i += 2)
			ans.push_back({even[i], even[i + 1]});
		for(int i = 0; i < n - 1; i++)
			cout << ans[i].first << " " << ans[i].second << endl;
	}
	return 0;
}