Write a program to control the action of a chocolate machine. Display a message to ask what kind of chocolate is required: Plain (30p), Brazil nut (35p), Luxury (50p). Use keyboard to get the input character. This input must be validated as P, B or L depending on the choice. Then money must be requested, in the form: Please insert 30p depending on the selection. Display the message until the required amount has been input. If too much has been inserted, then display a message indicating the amount of change owing. And also display a message indicating Thanks for Buying. Try to use the function.