#include <iostream>
#include <vector>
#include <algorithm>
 
using namespace std;
 
int main() {
	int n;
    while (cin >> n) {
		//cout << "n" << n << endl;
		if(!cin) break;
 
		vector<vector<int>> bids(n, vector<int>(3)); // 競標價格
		for (int i = 0; i < n; ++i) {
			for (int j = 0; j < 3; ++j) {
				cin >> bids[i][j];
			}
		}
 
		bool flow_mark = false;
		short get_plear = 0;
		long long n_base = bids[0][0] * 1000000LL + bids[0][1] * 1000LL + bids[0][2];
		//cout << "n_base " << n_base << endl;
		for (int i = 1; i < n; ++i) {
			long long n_ram = bids[i][0] * 1000000LL + bids[i][1] * 1000LL + bids[i][2];
			//cout << "n_ram  " << n_ram << endl;
			if(n_base < n_ram){
				n_base = n_ram;
				flow_mark = false;
				get_plear = i;
				//cout << "change" <<endl;
			}else if(n_base == n_ram){
				flow_mark = true;
				//cout << "equal" <<endl;
			}
			//cout << "no change" <<endl;
			//cout << "n_base2 " << n_base << endl << endl;
		}
		get_plear++;
		cout << (flow_mark ? "F" : to_string(get_plear)) << endl;
    }
 
    return 0;
}
 

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