#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
int main() {
while (cin) {
int n;
cin >> n;
if(!cin) break;
//cout << 'n' << n << endl;
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];
for (int i = 1; i < n; ++i) {
long long n_ram = bids[i][0] * 1000000LL + bids[i][1] * 1000LL + bids[i][2];
if(n_base < n_ram){
n_ram = n_base;
flow_mark = false;
get_plear = i;
}else if(n_base == n_ram){
flow_mark = true;
}
}
get_plear++;
cout << (flow_mark ? "F" : to_string(get_plear)) << endl;
}
return 0;
}
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