using System;

class S26_cipher{
  public static int Main(string[] args){
    char[] s = new char[1024];
    int asc;

    string s1 = Console.ReadLine();
    s = s1.ToCharArray();

    for(int i = 0; i < s.Length; i++){
      asc = ((int)s[i] - 65 - (i+1))%26;
      if(asc < 0){
        s[i] = (char)(asc + 26 + 65);
      }else{
        s[i] = (char)(asc + 65);
      }
    }

    Console.WriteLine(s);
    return 0;
  }
}