using System;

public class Program
{

    public static void Main(string[] args)
    {
        var s = Console.ReadLine();
        string ans = string.Empty;
        int mod = 26;
        for (var i =0; i< s.Length; i++)
        {
            int add = (((s[i] - 'A') - (i+1)) % mod + mod ) % mod;
            ans += (char)('A' + add);
        }
        Console.WriteLine(ans);
    }
}