exercise 21 full solution

8:40

23:43

21:52

21:52

21:36

20:44

15:20

48:59

21:09

11:06

25:37

5:49:55

9:46

13:10

22:24

10:28

7:04

43:48

1:06:12

1:29:52

16:58

2:21:10

13:53

6:11

1:37:14

8:21

1:45:40

8:59

4:13:36

40:56

21:27

19:30

6:30

15:44

2:53:29

00:36

21:54

13:30

29:51

3:22

8:20

4:49

45:15

4:10:33

29:10

1:08:09

9:37

1:10:11

2:13

00:24

1:37:15

10:23

5:16

22:18

32:03

21:06

1:23:59

25:30

26:45

1:16:39