using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Runtime.CompilerServices;
using System.Text;
using System.Threading.Tasks;

namespace yukicore
{
    class Program
    {
        //no18
        static void Main(string[] args)
        {
            byte[] strs = Console.ReadLine()
                .ToCharArray()
                .Select(x => (byte) x)
                .Select(x => (byte) (x - 65))
                .ToArray();
            var nums = Enumerable.Range(1, strs.Length).ToArray();

            for (int i = 0; i < strs.Length; i++)
            {
                var tmp = (strs[i] - nums[i]) % 26;
                strs[i] = (byte) (tmp < 0 ? 26 + tmp : tmp);
                strs[i] += 65;
            }
            var rtn = new string(strs.Select(x => (char) x).ToArray());
            Console.WriteLine(rtn);
        }



    }
}