#include <iostream>
#include <vector>
#include <tuple>
#include <algorithm>
using namespace std;
int main(){
	int HA, WA;
	cin >> HA >> WA;
	int HB, WB;
	cin >> HB >> WB;
	int HC, WC;
	cin >> HC >> WC;
	vector<tuple<int, int, char>> P;
	P.push_back(make_tuple(- HA, WA, 'A'));
	P.push_back(make_tuple(- HB, WB, 'B'));
	P.push_back(make_tuple(- HC, WC, 'C'));
	sort(P.begin(), P.end());
	for (int i = 0; i < 3; i++){
		cout << get<2>(P[i]) << endl;
	}
}