I need help writing a java code that does

An electronics company sells circuit boards at a 40 % profit. If you know the retail price of a circuit board, you can calculate its profit with the following formula:

Profit = Retail price x 0.4

Write a program that asks the user for the retail price of a circuit board, calculates the amount of profit earned for that product, and displays the results on the screen.

It will also require comments

I need it to do this without a "Could not find or load main class" error. Or at least an explanation of how to fix that error if it comes up. Thank you very much