using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Text.RegularExpressions;

class Program
{
	static void Main(string[] args)
	{
		var bro = new Brother[3];
		for (int i = 0; i < 3; i++)
		{
			bro[i] = new Brother
			{
				Height = int.Parse(Console.ReadLine()),
				Name = (char)('A' + i)
			};
		}
		var ordered = bro.OrderByDescending(i => i.Height).Select(i => i.Name);
		foreach (var item in ordered)
		{
			Console.WriteLine(item);
		}
	}

	public class Brother
	{
		public int Height { get; set; }
		public char Name { get; set; }
	}
}