hollow block calculation

4:01

5:25

9:53

12:59

00:55

24:14

3:13

10:00

11:52

4:58

10:31

11:36

23:52

56:33

3:56

8:36

3:10

7:01

6:34

2:33

4:52

4:12

16:49

3:07

2:27

17:37

8:11

2:23

23:19

2:45

10:10

6:13

1:10

25:26

10:26

6:44

5:13

2:02

2:30

3:00

6:41

13:18

5:16

4:48

14:50

8:39

6:03

2:47

4:13

2:17

4:53

2:12

14:15

5:20

10:57

4:10

3:08

2:35

13:20

6:03