#include <iostream>
#include <algorithm>
using namespace std;

struct H{
	int h, w;
	char name;
};

bool operator<(H &a, H &b){
	return a.h == b.h ? a.w > b.w : a.h < b.h;
}

int main(){
	H hs[3];
	for(int i = 0; i < 3; i++){
		int h, w;
		cin >> h >> w;
		hs[i].h = h;
		hs[i].w = w;
		hs[i].name = "ABC"[i];
	}
	sort(hs, hs + 3);
	reverse(hs, hs + 3);
	for(int i = 0; i < 3; i++){
		cout << hs[i].name << endl;
	}
	return 0;
}