//No.570 3人兄弟（その１）
#include<iostream>
#include<algorithm>
using namespace std;
void bubblesort(int _H[],char _NAME[]);
int main()
{
	int H[3];
	char NAME[3] = {'A','B','C'};
	for (int i = 0; i < 3; i++)cin >> H[i];
	bubblesort(H, NAME);
	for (int i = 0; i < 3; i++)cout << NAME[i] << endl;
	return 0;
}

void bubblesort(int _H[], char _NAME[3]) {
	for (int i = 0; i < 3 - 1; i++) {
		for (int j = 3-1; j>i; j--) {
			if (_H[j - 1] < _H[j]) {
				swap(_H[j - 1], _H[j]);
				swap(_NAME[j - 1], _NAME[j]);
			}
		}
	}
}