#define _USE_MATH_DEFINES
#include <bits/stdc++.h>
using namespace std;
signed main() {
  ios::sync_with_stdio(false); cin.tie(0);
  int a, b, c;
  cin >> a >> b >> c;
  int mx = max({a, b, c});
  if (mx == a) cout << "A" << endl;
  if (mx == b) cout << "B" << endl;
  if (mx == c) cout << "C" << endl;
  return 0;	
}
