for pratyush in range(int(input())):
n=int(input())
l=list(map(int,input().split()))
o,e=0,0
a,b=[],[]
for i in range(2*n):
if l[i]%2==0:
b.append(i)
e+=1
else:
o+=1
a.append(i)
if o%2==1:
a.pop()
b.pop()
else:
if o>1:
a.pop()
a.pop()
o-=2
else:
b.pop()
b.pop()
e-=2
for i in range(0,len(a),2):
print(a[i]+1,a[i+1]+1)
for i in range(0,len(b),2):
print(b[i]+1,b[i+1]+1)#include <bits/stdc++.h>
using namespace std;
void solve()
{
int n,cnt;
cin >> n;
int a[2 * n];
cnt=0;
vector<int> even; // carry index
vector<int> odd;
for (int i = 0; i < 2 * n; i++)
{
cin >> a[i];
if (a[i] % 2 == 0)
{
even.push_back(i + 1);
}
else
{
odd.push_back(i + 1);
}
}
for (int i = 0; i < even.size(); i += 2)
{
if (i + 1 < even.size() and cnt<n-1)
{
// cout<<"before";
// cout<<cnt<<"\n";
cout << even[i] << " " << even[i + 1] << "\n";
cnt++;
// cout<<cnt<<endl;
// cout<<"after";
}
}
for (int i = 0; i < odd.size(); i += 2)
{
if (i + 1 < odd.size() and cnt<n-1)
{
// cout<<"before";
// cout<<cnt<<"\n";
cout << odd[i] << " " << odd[i + 1] << "\n";
cnt++;
// cout<<cnt<<"\n";
// cout<<"after";
}
}
// cout<<cnt<<endl;
}
int main()
{
int t;
cin >> t;
// t = 1;
while (t--)
{
solve();
}
}1399A - Remove Smallest | 208A - Dubstep |
1581A - CQXYM Count Permutations | 337A - Puzzles |
495A - Digital Counter | 796A - Buying A House |
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1472B - Fair Division | 1281C - Cut and Paste |
141A - Amusing Joke | 112A - Petya and Strings |
677A - Vanya and Fence | 1621A - Stable Arrangement of Rooks |
472A - Design Tutorial Learn from Math | 1368A - C+= |
450A - Jzzhu and Children | 546A - Soldier and Bananas |
32B - Borze | 1651B - Prove Him Wrong |
381A - Sereja and Dima | 41A - Translation |
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292B - Network Topology | 1339A - Filling Diamonds |
910A - The Way to Home | 617A - Elephant |
48A - Rock-paper-scissors | 294A - Shaass and Oskols |