using System;
using System.Linq;
using System.Collections;
using System.Collections.Generic;

class Program {
    static void Main(string[] args) {
        Dictionary<char, int> di = new Dictionary<char, int>();
        for (int i = 0; i < 3; i++) {
            int a = int.Parse(Console.ReadLine());
            di.Add((char)('A' + i), a);
        }
        var sorted = di.OrderByDescending(x => x.Value);
        foreach (var i in sorted) {
            Console.WriteLine(i.Key);
        }
    }
}