#include <iostream>
#include <vector>
#include <utility>
#include <algorithm>

using namespace std;

int main() {
  int a, b, c;
  vector<pair<int, char>> v={{0, 'A'}, {0, 'B'}, {0, 'C'}};

  for (int i=0; i<3; i++) {
    cin >> v[i].first;
  }

  sort(v.begin(), v.end(), greater<pair<int, char>>());

  for (int i=0; i<3; i++) {
    cout << v[i].second << endl;
  }
  return 0;
}