import java.util.*;

public class Main {
    public static void main(String... args){
        Scanner sc=new Scanner(System.in);
        String s=sc.next();
        for (int i = 0; i < s.toCharArray().length; i++) {
            int c=(int)s.charAt(i)-'A'-i-1;
            while(c<0){
                c+=('z'-'a'+1);
            }
            c+='A';
            System.out.print((char)c);
        }
        System.out.println();
    }
}