#include <stdio.h>
#define SIZE 11
int message(char *, int);

int main( ) {
   int i=0, ok = 1;
   char array[SIZE] = "Hnpc Kvbl!";

   while(ok) {
      /* recall: single line if/else statements do not
         require opening/closing '{' '}' brackets */
      if(i != 4 && i != 9)
            ok = message(&array[i], i);
      else
         printf("%c", array[i]);
      i++;
   }
   return 0;
}

int message(char *y, int val) {
   if(val % 2 == 0)
      *y -= 1;
   else
      *y = *y + 1;
   printf("%c", *y);
   return val < 9 ? 1 : 0;
}