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

int main()
{
	vector<pair<int, char>> h( 3 );
	h[0].second = 'A';
	h[1].second = 'B';
	h[2].second = 'C';
	cin >> h[0].first >> h[1].first >> h[2].first;

	sort( h.rbegin(), h.rend() );

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