Issue raised in more clearer form by other users, closing this for now.

I would suggest making the following changes to resolve this

Every Tuesday, my friend Sergio visits a pizzeria and buys a pizza. Sergio always gives a 200 hryvnias banknote, as the pizza's price is always less than 200 hryvnias.

Prices sometimes change and the pizzeria needs a special program to calculate the amount of money they need to return. The pizzeria's owner studied qbasic in college, so he wrote javascript as qbasic. Please, help him and fix a function that calculates the change for a pizza.