You are a thief and you steal food. When you're stealing food you can steal either tomatoes, onions, or potatoes. A tomato weighs 4 pounds, an onion weighs 1 pound, and a potato weighs 2 pounds. You can only steal 15 pounds of stuff. A tomato is worth 0.5 dollars, an onion is worth 2 dollars, and potatoes are worth 3 dollars. You have to steal at least one tomato and one potato. You cannot steal a negative amount of something.

How many tomatoes do you steal?