#include<iostream>
using namespace std;
int main() {
	int a, b, c;
	cin >> a >> b >> c;
	if (a > b && a > c){
		cout << "A";
		}
	if (b > c && b > a) {
		cout << "B";
	}
	if (c > a && c > b) {
		cout << "C";
	}
	cout << endl;
}
