#include<iostream>
#include<vector>
#include<algorithm>

using namespace std;

struct  Person
{
	char name;
	int height;
	int weight;
	bool operator<(const Person& p) const {
		return  (height == p.height) ? weight<p.weight : height>p.height;
	}
};

int main() {

	vector<Person> data;
	
	for (int i = 0;i < 3;i++) {
		int h, w;
		cin >> h >> w;
		Person p;
		p.height = h, p.weight = w;
		switch (i)
		{
		case 0:p.name = 'A';break;
		case 1:p.name = 'B';break;
		case 2:p.name = 'C';break;
		}
		data.push_back(p);
	}

	sort(data.begin(),data.end());

	for (int i = 0;i < data.size();i++) {
		cout << data[i].name<<endl;
	}

	return 0;
}