#include <stdio.h>
int main(void){
    char s[1025];
    int i = 0, j;
    scanf("%s", s);
    while(s[i] != '\0'){
        for(j = 0; j < i+1; j++){
            s[i]--;
            while(s[i] < 'A'){
                s[i] += 26;
            }
        }
        i++;
    }
    printf("%s\n", s);
    return 0;
}