# 1. Method sellItem: sell items at 80% reduction (item worth $100 would sell for $80) # 2. Create a upper limit (4 items) for your inventory list, keep track of this limit and allow up to 4 items
# to be purchased, if the inventory is full (4 items), disable buying items by showing an error message (print it out).
# 3. Write a short paragraph explaining how your program works, be as detailed as possible by explaining every step of your program.