#include <stdlib.h>

char *fanis(char* r, int k) {
    char* w = malloc(0);
    int i = 0;  
    if (w != NULL)
        for (; *r; *w++ = k + *r++)
          i++;
    return w - i;
}

#include <stdlib.h>

char *fanis(char* r, int k) {
    char* w = malloc(0);
    for (int i = 0; r[i]; i++)
        w[i] = k + r[i];
    return w;
}

#include <stdlib.h>

char *fanis(char* r, int k) {
    char* w = malloc(0);
    for (int i = 0; r[i]; w[i] = k + r[i], i++);
    return w;
}