import java.util.Scanner;

public class Main{

	static Scanner s=new Scanner(System.in);

	public static void main(String __[]){
		input();
		solve();
	}

	private static void input(){
	}

	private static void solve(){
		char c[]=s.next().toCharArray();
		for(int i=0;i<c.length;i++) {
			c[i]=(char)(((c[i]-'A'-i-1+260)%26)+'A');
		}
		System.out.println(String.valueOf(c));
	}
}