#include <bits/stdc++.h>

#define rep(i,n) for(int i=0;i<(n);i++)

using namespace std;

int main(){
	vector<tuple<int,int,char>> a(3);
	rep(i,3){
		cin>>get<0>(a[i])>>get<1>(a[i]);
		get<2>(a[i])='A'+i;
	}
	sort(a.rbegin(),a.rend());
	rep(i,3) cout<<get<2>(a[i])<<'\n';
	return 0;
}