construct a staircase

9:21

13:29

8:26

29:31

12:45

19:27

19:27

9:37

8:46

8:46

6:15

14:31

12:29

9:11

6:29

8:38

9:24

13:02

6:29

7:21

6:49

کوتاه

7:16

6:58

8:39

4:21

11:07

1:08

6:51

3:49

1:28:37

1:29:14

1:29:15

2:18

2:08

1:59

8:30

1:22:52

1:17

2:50