A boy has a box that can hold 20,000 jellybeans. In day 1, there are 6,000 jellybeans initially. Each day, the boy can buy or sell jellybeans at given prices.

Day 1: Selling Price $3, Purchase Price $8

2: 6,8

3: 7,2

4: 1,3

5: 4,4

6: 5,3

7: 5,3

8: 1,2

9: 3,5

10: 2,5

- The boy can sell any amount of jellybeans up to his initial stock at the current day's selling price

- He can buy as many jellybeans (at the current day's purchase price) from other kids as he wants, but this is subject to the capacity of the box

What buying/selling plan should the boy pursue to maximize profits?