#include <bits/stdc++.h>
using namespace std;

int N = 3;

int main() {
	cin.sync_with_stdio(0), cin.tie(0), cout.tie(0);
	int h[N];
	string c = "ABC";
	vector<pair<int, char>> AB(N);
	for (int i = 0; i < N; i++) {
		cin >> h[i];
		AB[i] = make_pair(h[i], c[i]);
	}
	sort(AB.begin(), AB.end());
	reverse(AB.begin(), AB.end());
	for (int i = 0; i < N; i++) {
		cout << AB[i].second << endl;
	}
}