Lily goes to the supermarket. She has $60. She needs to buy 6 items: celery, cereal, bread, milk, potatoes, and coffee. She finds a stalk of celery for $5, cereal for 50% off $12, bread for $8, and milk for 10% off $10. She finds potatoes for $1 each and buys 6. How many dollars does she have left to spend on coffee?
Solve this problem.