#include <stdio.h>
#include <string.h>

char abc[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";

int abc_num(char a){
    int i, ret;
    for(i = 0; i < 26; i++){
        if(a == abc[i]){
            ret = i;
        }
    }
    return ret;
}

int main(){
    char str[1025];
    int len, i, pos, str_pos;

    scanf("%s", str);
    len = strlen(str);
    //printf("len = %d\n", len);

    for(i = 0; i < len; i++){
        pos = abc_num(str[i]);
        if(pos - (i%26 + 1) >= 0){
            str_pos = pos - (i%26 + 1);
        }else{
            str_pos = pos - (i%26 + 1) + 26;
        }
        //printf("%d\n", str_pos);
        str[i] = abc[str_pos];
    }
    //printf("len2 = %ld\n", strlen(str));
    printf("%s\n", str);

}