#include <bits/stdc++.h>
using namespace std;
#ifdef LOCAL
  #include "settings/debug.cpp"
  #define _GLIBCXX_DEBUG
#else
  #define Debug(...) void(0)
#endif
using ll = long long;
#define rep(i, n) for (int i = 0; i < (n); ++i)

int main() {
  vector<pair<int, char>> v(3);
  rep(i, 3) {
    int a;
    cin >> a;
    v[i] = { a, 'A' + i };
  }
  sort(v.rbegin(), v.rend());
  rep(i, 3) cout << v[i].second << endl;
  return 0;
}