// iostream is too mainstream
#include <cstdio>
// bitch please
#include <iostream>
#include <algorithm>
#include <cstdlib>
#include <vector>
#include <set>
#include <map>
#include <queue>
#include <stack>
#include <list>
#include <cmath>
#include <iomanip>
#define dibs reserve
#define OVER9000 1234567890123456789LL
#define ALL_THE(CAKE,LIE) for(auto LIE =CAKE.begin(); LIE != CAKE.end(); LIE++)
#define tisic 47
#define soclose 1e-8
#define chocolate win
// so much chocolate
#define patkan 9
#define ff first
#define ss second
#define abs(x) ((x < 0)?-(x):x)
#define uint unsigned int
#define dbl long double
using namespace std;
// mylittledoge

int main() {
	cin.sync_with_stdio(0);
	cin.tie(0);
	int T;
	cin >> T;
	for(int t =0; t < T; t++) {
		int N;
		cin >> N;
		int x =0;
		double y =-(1e8);
		for(int i =0; i < N; i++) {
			int a,b,c;
			cin >> a >> b >> c;
			double r =0.5*b/a;
			double z =-a*r*r+b*r+c;
			y =max(y,z);
			if(z >= y-0.1) x =i+1;}
		cout << x << "\n";}
	return 0;}

// look at my code
// my code is amazing