#include <iostream>
#include <vector>
#include <map>
#include <set>
#include <queue>
#include <string>
#include <iomanip>
#include <algorithm>
#include <cmath>
#include <stdio.h>
using namespace std;
#define int long long
int MOD = 1000000007;
signed main() {
	cin.tie(0);
	ios::sync_with_stdio(false);
	vector<pair<int, char> >A(3);
	int a;
	for (int i = 0; i < 3; i++) {
		cin >> a;
		A[i].first = -a;
		A[i].second = char(i + 'A');
	}
	sort(A.begin(), A.end());
	for (int i = 0; i < 3; i++) {
		cout << A[i].second << endl;
	}
}