#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
#include <utility>
using namespace std;

int main(void) {
	int x;
	string str = "ABC";
	vector <pair<int, char>> v;
	for (int i = 0; i < 3; i++) {
		cin >> x;
		v.push_back({ x,str[i] });
	}
	sort(v.begin(), v.end());
	reverse(v.begin(),v.end());
	for (int i = 0; i < 3; i++)
		printf("%c\n", v[i].second);
	return 0;
}