(10) starting
(20) input   is 0
(40) partial is 0
(50) partial is 0
(60) partial is 0
(80) result  is 0
(90) starting
(100) input   is 1
(120) partial is 0
(130) partial is 1
(140) partial is 2
(160) result  is 3
(170) starting
(180) input   is 2
(200) partial is 0
(210) partial is 2
(220) partial is 4
(240) result  is 6
(250) starting
(260) input   is 3
(280) partial is 0
(290) partial is 3
(300) partial is 6
(320) result  is 9
(330) starting
(340) input   is 4
(360) partial is 0
(370) partial is 4
(380) partial is 8
(400) result  is 12
(410) starting
(420) input   is 5
(440) partial is 0
(450) partial is 5
(460) partial is 10
(480) result  is 15
(490) starting