#include <bits/stdc++.h>
using namespace std;

int main() {
  vector<pair<int, char>> V(3);
  int n;
  cin >> n;
  V.at(0) = {n, 'A'};
  cin >> n;
  V.at(1) = {n, 'B'};
  cin >> n;
  V.at(2) = {n, 'C'};
  sort(V.rbegin(), V.rend());
  for (int i = 0; i < 3; i++) cout << V.at(i).second << "\n"; 
}