#include<iostream>
#include<string>
#include<string.h>
#include<algorithm>
#include<stdio.h>
#include<cmath>
#include<vector>
#include<utility>
#include<stack>
#include<queue>
#include<list>

#define FOR(i, a, b) for(int i=(a);i<=(b);i++)
#define RFOR(i, a, b) for(int i=(a);i>=(b);i--)
#define MOD 1000000007
#define INF 1000000000

using namespace std;


int main(void) {
	vector<pair<int, char>>h(3);

	FOR(i, 0, 2) {
		cin >> h[i].first;
		h[i].second = 'A' + i;
	}
	sort(h.begin(),h.end());
	RFOR(i, 2, 0) {
		cout << h[i].second << endl;
	}

	return 0;
}