#include <iostream>
#include <string>
#include <vector>
#include <utility>
using namespace std;
int main(void){
  int h[3],w[3];
  char x[3]={'A','B','C'};
  for(int i=0;i<3;i++)
    cin >> h[i] >> w[i];
  for(int i=0;i<2;i++){
    for(int j=i;j<3;j++){
      if(h[i]<h[j]){
        swap(h[i],h[j]);
        swap(w[i],w[j]);
        swap(x[i],x[j]);
      }
    }
  }
  for(int i=0;i<2;i++){
    if(h[i]==h[i+1]){
      if(w[i]>w[i+1]){
        swap(w[i],w[i+1]);
        swap(x[i],x[i+1]);
      }
    }
  }
  cout << x[0] << "\n" << x[1] << "\n" << x[2] << "\n";
  return 0;
}