#define  _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <algorithm>
#include <utility>
#include <functional>
#include <cstring>
#include <queue>
#include <stack>
#include <math.h>
#include <iterator>
#include <vector>
#include <string>
#include <set>
#include <math.h>
#include <iostream>
#include <random>
#include<map>
#include <fstream>
#include <iomanip>
#include <time.h>
#include <stdlib.h>
#include <list>
#include <typeinfo>
#include <list>
#include <set>
#include <assert.h>
using namespace std;
#define eps 0.000000001
#define LONG_INF 10000000000000000
#define GOLD 1.61803398874989484820458
#define MAX_MOD 1000000007
#define MOD 998244353
#define seg_size 65536*2
#define REP(i,n) for(long long i = 0;i < n;++i)
#define cycle_per_sec 2806192512
int main() {
	string hoge[3] = { "A","B","C" };
	vector<pair<int, int>> hogea;
	for (int i = 0; i < 3; ++i) {
		int a;
		cin >> a;
		hogea.push_back(make_pair(1000 - a, i));
	}
	sort(hogea.begin(), hogea.end());
	for (int i = 0; i < 3; ++i) {
		cout << hoge[hogea[i].second] << endl;
	}
	return 0;
}