You live in a Desert oasis and grow miniature watermelons that are worth a great deal of money, if you can get them to the market 15 kilometers away across the desert. Your harvest this year is 45 watermelons, but you have no way to get them to the market, expect to carry them across the desert. You have a backpack that holds up to 15 melons, the maximum number you can carry at a time. To walk across the desert. you need a certain amount of fluid and nourishment that is supplied by the melons you carry. For each kilometer you walk (In either diction), one mellon must be eaten.

Your challenge is to find a way to get as many melons as possible to the market.

?????