import java.util.Scanner;
import java.util.Arrays;

class S26_cipher{
  public static void main(String[] argd){
    Scanner sc = new Scanner(System.in);
    int as;
    String s;

    s = sc.next();

    for(int i = 0; i < s.length(); i++){
      char c = s.charAt(i);
      as = ((int)c - 65 - (i+1)) % 26;
      if(as < 0){
        c = (char)(as +26 + 65);
      }else{
        c = (char)(as + 65);
      }
      System.out.print(c);
    }
    System.out.println("");

  }
}