i need to compre two strings and to compare them using recursion. in the process to count the number of the differences up to two.
i tried this:

```
int strcmp1(char *str1, char *str2){
int err=0;
if(strlen(str1)-strlen(str2)>1 ||strlen(str1)-strlen(str2)<1)
    return 0;

 if (*str1 =='\0' && *str2=='\0'|| err==2)
    return err;

if (*str1!=*str2)
    err++;

return strcmp1(str1 + 1, str2 + 1);
}

```

the code i wrote returns only 0 or 1, not the amount of differences...
can you please tell me what am i doing wrong?
thx :)