problems管 （1987） 19

8 mins 45 secs

8 mins

5 mins 2 secs

6 mins 1 sec

8 mins 30 secs

9 mins

7 mins 38 secs

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49 mins 20 secs

7 mins 44 secs

8 mins 14 secs

11 mins 29 secs

12 mins 42 secs

12 mins 42 secs

12 mins 42 secs

12 mins 42 secs

12 mins 42 secs

12 mins 42 secs

12 mins 42 secs

12 mins 42 secs

12 mins 42 secs

12 mins 42 secs

12 mins 42 secs

22 mins 31 secs

12 mins 42 secs

12 mins 7 secs