I have input of the form `(first_string*second_string)` where `*` can be one of three characters, `x`, `y` or `z`. I need to extract `first_string` and `second_string` as strings of their own.

I'm able to do this with `strchr` if `*` was always the same, but I'm not sure how to do this when `*` is one of three possible characters.

I'm assuming I need to use a function of the form

```
int star(char g) {
    if (g == 'x' || g == 'y' || g == 'z') {
        return 1;
    }
    else {
        return 0;
    }
}

```

but I'm not sure how to proceed from here. Can anyone help me out?