//inlclude前用define 
#define _USE_MATH_DEFINES

//include
#include<iostream>
#include<string>
#include<algorithm>
#include<vector>
#include<cmath>

using namespace std;
//typedef
typedef vector<int> VI;
typedef vector<string> VS;
typedef vector<char> VC;

int main() {
	int a[3];
	for (int i = 0; i < 3; i++) cin >> a[i];

	int maxv = -1,memo;
	char ans[3];
	for (int i = 0; i < 3; i++) {
		if (max(maxv, a[i]) == a[i]) {
			maxv = a[i];
			memo = i;
		}
	}
	ans[memo] = 'A';
	if (memo == 1) {
		if (a[2] < a[3]) {
			ans[3] = 'B'; ans[2] = 'C';
		} else {
			ans[2] = 'B'; ans[3] = 'C';
		}
	} else if (memo == 2) {
		if (a[1] < a[3]) {
			ans[3] = 'B'; ans[1] = 'C';
		}
		else {
			ans[1] = 'B'; ans[3] = 'C';
		}
	} else {
		if (a[1] < a[2]) {
			ans[2] = 'B'; ans[1] = 'C';
		}
		else {
			ans[1] = 'B'; ans[2] = 'C';
		}
	}

	for (int i = 0; i < 3; i++) {
		cout << ans[i] << endl;
	}
	return 0;
}