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

class Task3
{
    static void Main()
    {
        int N = int.Parse(Console.ReadLine());
        int[] sheets = new int[11];
        sheets[0] = 1024;
        for (int i = 1; i < 11; i++)
        {
            sheets[i] = sheets[i - 1] / 2;
        }
        for (int i = 0; i < 11; i++)
        {
            if (N / sheets[i] == 0)
            {
                Console.WriteLine("A{0}",i);
            }
            N = N % sheets[i];
        }
    }
}