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

namespace
{
char H[ 220 ];
}

int main()
{
int i;
int a, b, c;

	cin >> a;
	cin >> b;
	cin >> c;
	H[ a ] = 'A';
	H[ b ] = 'B';
	H[ c ] = 'C';

	for( i = 200; i >= 150; i-- )
	{
		if( H[ i ] ) cout << H[ i ] << endl;
	}
}