#include<bits/stdc++.h>
using namespace std;
using ll = long long;
#define rep(i,m,n) for(int i=m; i<n; ++i)
#define repl(i,m,n) for(ll i=m; i<n; ++i)

struct Person{
    int H, W;
    char c;

    bool operator < (const Person &p){
        if(H == p.H){
            return W < p.W;
        }else{
            return H > p.H;
        }
    }
};

int main(){
    Person P[3];
    rep(i, 0, 3){
        cin >> P[i].H >> P[i].W;
        P[i].c = char('A' + i);
    }

    sort(P, P+3);

    rep(i, 0, 3){
        cout << P[i].c << endl;
    }

    return 0;
}