using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace template
{
    class Program
    {
        static void Main(string[] args)
        {
            int a = int.Parse(Console.ReadLine());
            int b = int.Parse(Console.ReadLine());
            int c = int.Parse(Console.ReadLine());
            int[] x = new int[] { a, b, c };
            int[] ret = new int[] { a, b, c };
            Array.Sort(x); Array.Reverse(x);
            for (int i = 0; i < 3; i++)
            {
                Console.WriteLine('A' + Array.IndexOf(ret, x[i]));
            }
        }
    }
}