PRG$-4.$ Modify PRG$-3$ to add anther class named SalaryHourlyEmployee whose ob$-$

ject receives a fixed amount of salary per month and extra pay if she works

more than $180$ hours per month using the same rate received by an hourly

employee. Use two more abstract classes, SalaryType and HourlyType to

avoid multiple inheritance $($Mixin classes$)$ as shown below. Write the inter$-$

face files, the implementation files for all classes and then test them in an

annlication file $($The samnle int main $()$ is stated as follows $)$

int main $()$

$\{$

$//$ Handling a salary employee

SalaryEmployee john $("$John$",\text{'}$A$\text{'},$ "Pape", $2500)$;

john.print$()$;

$//$ Handling an hourly employee

HourlyEmployee lucie $("$Lucie$",\text{'}$C$\text{'},$ "Bush" $,70,20\mathrm{.}0)$;

lucie.print $()$;

$//$ Handling a salary$-$hourly employee

SalaryHourlyEmployee ann $("$Ann$",\text{'}$A$\text{'},$ "White", $3500,230,20\mathrm{.}0)$;

ann.print $()$;

return $0$;

$\}$