#include<stdio.h>

int main(void){

	char str[1024];
	int num;

	scanf("%s",str);


	for(int i = 0;str[i] != '\0';i++){
		num = (str[i]-'A'-(i+1))%26+'A';

		if(num < 'A'){
			num += 26;
		}
		printf("%c",num);
		//printf("%d,%c\n",num,num);
	}
	printf("\n");


	return 0;
}