#include<iostream>
#include<functional>
#include<vector>
#include<utility>
#include<algorithm>

int main() {
	std::vector<std::pair<int, char> > v;
	int a;
	for (int i = 0; i < 3; i++) {
		std::cin >> a;
		v.push_back(std::make_pair(a, 'A' + i));
	}
	std::sort(v.begin(), v.end(), std::greater<std::pair<int, char> >());

	for (int i = 0; i < 3; i++) {
		std::cout << v[i].second << std::endl;
	}

}