I'm completely lost with this math problem: Lionel went to the grocery store and bought 14 boxes of Graham crackers and 15 packets of Oreos. To make an Oreo cheesecake, Lionel needs 2 boxes of Graham crackers and 3 packets of Oreos. After making the maximum number of Oreo cheesecakes he can with the ingredients he bought, how many boxes of Graham crackers would he have left over?
Can you give me a hand?