using System;

public class Hello
{
    public static void Main()
    {
        var s = Console.ReadLine().Trim();
        var ans = "";
        for (int i = 0; i < s.Length; i++)
            ans += getRev(s[i], i + 1);
        Console.WriteLine(ans);
    }
    public static char getRev(char a, int b)
    {
        var bs = (int)'A';
        var w = (int)a - b;
        while (w < bs) w += 26;
        return (char)w;
    }
}