#include<bits/stdc++.h>
int main(){
    std::vector<std::tuple<int,int,int>>a(3);
    for(int i=0;i<3;i++){
        int x,y;std::cin>>x>>y;
        a.at(i)=std::make_tuple(-x,y,i);
    }
    std::sort(a.begin(),a.end());
    for(int i=0;i<3;i++){
        std::cout<<(char)('A'+std::get<2>(a.at(i)))<<std::endl;
    }
}