Business requirement

A small shop needs a screen that calculates a bill from item price and quantity, with a basic bulk discount.

1. Accept Price and Quantity.
2. Calculate Subtotal as Price × Quantity.
3. Apply a 10% discount when Subtotal is at least ₹1,000; otherwise apply no discount.
4. Display Subtotal, Discount, and Total.
5. Reject zero or negative inputs.