#include <bits/stdc++.h>
using namespace std;
#define rep(i,n) for(int i=0; i<(n); i++)
#define all(x) (x).begin(),(x).end()

int main(){
	int n=3;
	vector<tuple<int,int, string>> vt;
	
	int a,b; string c;
	cin>>a>>b; a*=-1; c="A";
	vt.emplace_back(a,b,c);
	
	cin>>a>>b; a*=-1; c="B";
	vt.emplace_back(a,b,c);
	
	cin>>a>>b; a*=-1; c="C";
	vt.emplace_back(a,b,c);
	
	sort(all(vt));
	
	for(auto x:vt) cout << get<string>(x) << endl;
	
}