using System;

namespace No18_1{
    public class Program{
        public static void Main(string[] args){
            var charArray = Console.ReadLine().ToCharArray();
            var length = charArray.Length;

            for(var i = 0; i < length; i++){
                var sub = i + 1;
                while(sub > 26) sub -= 26;
                charArray[i] -= (char) sub;
                if(charArray[i] < 'A') charArray[i] += (char) 26;
            }

            foreach(var c in charArray){
                Console.Write(c);
            }

            Console.WriteLine();
        }
    }
}