I want to get the following code piece work:

```
#define READIN(a, b) if(scanf('"#%d"', '"&a"') != 1) { printf("ERROR"); return EXIT_FAILURE; }

int main(void)
{
    unsigned int stack_size;
    printf("Type in size: ");
    READIN(d, stack_size);
}

```

I don't get it, how to use directives with the `#` operator. I want to use the `scanf` with print ERROR etc. several times, but the `"'"#%d"'` & `'"&a"'"` is I think completely wrong. Is there any way to get that running? I think a macro is the best solution or not?