A market owner wants to start a jam business. He can either sell one unit of jam to customers in a set of small packets or jugs. A set of small packets can hold 1000 ml of jam while a jug can hold 1250 ml of jam. Since a set of small packets are more expensive to make, at least three times as many jugs must be used than sets of small packets. On the other hand, at least 35 sets of small packets should be filled. If the market owner has 65000 ml of jam, how many sets of small packets or jugs should be selected to maximize the total number of units that he can sell to his customers?