problems管 （1992） 13

8 mins

8 mins

5 mins 40 secs

8 mins 12 secs

9 mins 4 secs

10 mins 10 secs

6 mins 44 secs

10 mins 55 secs

10 mins 25 secs

7 mins 38 secs

12 mins 42 secs

12 mins 42 secs

8 mins 17 secs

12 mins 42 secs

12 mins 42 secs

12 mins 42 secs

12 mins 42 secs

8 mins

20 mins

12 mins 42 secs

12 mins 42 secs

12 mins 42 secs

7 secs

5 mins

14 mins 20 secs

10 mins 2 secs

12 mins