x y element range start container 25 25 outer after-after 25 100 after-after after-after 49 25 outer after 49 100 after after 50 25 outer middle 50 100 middle middle 149 25 outer middle 149 100 middle middle 150 25 outer before 150 100 before before 165 25 outer before-before 165 100 before-before before-before