#include <iostream>
#include <cstdio>
#include <vector>
#include <map>
#include <set>
#include <algorithm>
#include <string>
#include <cstdlib>
#include <stack>
#include <queue>
#include <cmath>
using namespace std;

int main() {
	char c[3] = { 'A','B','C' };
	pair<int,int>p[3];
	for (int i = 0; i <3 ; i++)cin >> p[i].first>>p[i].second;

	for (int i = 0; i < 2; i++) {
		for (int j = i + 1; j < 3; j++) {
			if (p[i].first > p[j].first) {
				int swap;
				swap = p[i].first;
				p[i].first = p[j].first;
				p[j].first = swap;

				char swapp;
				swapp = c[i];
				c[i] = c[j];
				c[j] = swapp;
			}
			else if (p[i].first == p[j].first) {
				if (p[i].second < p[j].second) {
					pair<int,int> swap;
					swap = p[i];
					p[i] = p[j];
					p[j] = swap;

					char swapp;
					swapp = c[i];
					c[i] = c[j];
					c[j] = swapp;
				}
			}
		}
	}

	for (int i = 2; i >= 0; i--)cout << c[i] << endl;

}