Exercise $3-$ Write a Python class called Product. The class should have fields called name, amount, and price, holding the product's name, the number of items of that product in stock, and the regular price of the product.

There should be a method get$\_$price that receives the number of items to be bought and returns the cost of buying that many items, where the regular price is charged for orders of less than $10$ items, a $10\%$ discount is applied for orders of between $10$ and $99$ items, and a $20\%$ discount is applied for orders of $100$ or more items.

There should also be a method called make$\_$purchase that receives the number of items to be bought and decreases amount by that much.