#include <bits/stdc++.h>
using namespace std;
int main()
{
    pair<int, int> p[3];
    vector<int> ran{0, 1, 2};
    int max_h;

    for (int i = 0; i < 3; i++) {
        cin >> p[i].first;
        cin >> p[i].second;
    }
    
    if (p[ran[0]].first < p[ran[1]].first) swap(ran[0], ran[1]);
    if (p[ran[1]].first < p[ran[2]].first) swap(ran[1], ran[2]);
    if (p[ran[0]].first < p[ran[1]].first) swap(ran[0], ran[1]);

    for (int i = 0; i < 2; i++) if (p[ran[i]].first == p[ran[i+1]].first) if (p[ran[i]].second > p[ran[i+1]].second) swap(ran[i], ran[i+1]);
    for (int i = 0; i < 3; i++) printf("%c\n", 'A' + ran[i]);
    return 0;
}