#include<iostream>
#include<functional>
#include<vector>
#include<utility>
#include<algorithm>

const int mod = 998244353;

struct Status {
	int h, w;
	char name;

	bool operator<(const Status& another) const {
		if (h != another.h) {
			return h > another.h;
		}
		return w < another.w;
	}
};

int main() {
	std::vector<Status> v(3);
	for (int i = 0; i < 3; i++) {
		std::cin >> v[i].h >> v[i].w;
		v[i].name = 'A' + i;
	}

	std::sort(v.begin(), v.end());

	for (int i = 0; i < 3; i++) {
		std::cout << v[i].name << std::endl;
	}
}