#include <bits/stdc++.h>
#define rep(i, ss, ee) for (int i = ss; i < ee; ++i)
using namespace std;

void solve() {
  vector<pair<int, string>> v(3);
  rep(i, 0, 3) { v[i].second = ('A' + i); }
  rep(i, 0, 3) { cin >> v[i].first; }
  sort(v.rbegin(), v.rend());
  rep(i, 0, 3) { cout << v[i].second << endl; }
}

int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  solve();
  getchar();
}