#include <bits/stdc++.h>

using namespace std;

#define fst(t) std::get<0>(t)
#define snd(t) std::get<1>(t)
#define thd(t) std::get<2>(t)
#define unless(p) if(!(p))
#define until(p) while(!(p))

using ll = long long;
using P = std::tuple<int,int,int>;

const int dx[8] = {-1, 1, 0, 0, -1, -1, 1, 1}, dy[8] = {0, 0, -1, 1, -1, 1, -1, 1};

int main(){
    std::cin.tie(nullptr);
    std::ios::sync_with_stdio(false);

    vector<P> v;
    for(int i=0;i<3;++i){
        int x, y;
        std::cin >> x >> y;

        v.emplace_back(-x, y, i);
    }

    sort(v.begin(), v.end());

    for(int i=0;i<3;++i){
        std::cout << (char)(thd(v[i]) + 'A') << std::endl;
    }
}