/* -*- coding: utf-8 -*-
 *
 * 570.cc: No.570 3人兄弟(その1) - yukicoder
 */

#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
#include<iostream>
#include<string>
#include<vector>
#include<map>
#include<set>
#include<stack>
#include<list>
#include<queue>
#include<deque>
#include<algorithm>
#include<numeric>
#include<utility>
#include<complex>
#include<functional>
 
using namespace std;

/* constant */

const int N = 3;

/* typedef */

typedef pair<int,int> pii;

/* global variables */

pii his[N];

/* subroutines */

/* main */

int main() {
  for (int i = 0; i < N; i++)
    scanf("%d", &his[i].first), his[i].second = i;
  sort(his, his + N, greater<pii>());

  for (int i = 0; i < N; i++) printf("%c\n", 'A' + his[i].second);
  return 0;
}