#include <bits/stdc++.h>
using namespace std;
int main(){
  int HA;
  cin >> HA;
  int HB;
  cin >> HB;
  int HC;
  cin >> HC;
  vector<pair<int, char>> H;
  H.push_back(make_pair(HA, 'A'));
  H.push_back(make_pair(HB, 'B'));
  H.push_back(make_pair(HC, 'C'));
  sort(H.rbegin(), H.rend());
  for (int i = 0; i < 3; i++){
    cout << H[i].second << endl;
  }
}