I am trying to use inheritance to create a class derived from `runtime_error`, but I keep getting an error even though this is the exact code used in exercises and as an example from the book. Here is the code:

```
class DivideZeroEx : public runtime_error
{
    public:
        DivideZeroEx()
            runtime_error( " attempt to divide by zero" )
};

```

Now I get an error stating that it expects a ; before the runtime\_error("attempt to divide by zero") line.