Given a set, weights, and an integer desired_weight, remove the element of the set that is closest to desired_weight (the closest element can be less than, equal to or greater than desired_weight), and associate it with the variable actual_weight. for example, if weights is (12, 19, 6, 14, 22, 7) and desired_weight is 18, then the resulting set would be (12, 6, 14, 22, 7) and actual_weight would be 19. if there is a tie, the element less than desired_weight is to be chosen. thus if the set is (2, 4, 6, 8, 10) and desired_weight is 7, the value chosen would be 6, not 8. assume there is at least one value in the set.