21:23
10
student
21:23 
11:19
5
05:16
3
27:36
5
13:59
5
09:00
1
39:03
3
07:20
5
20:48
1
09:40
4
05:52
7
11:13
4
30:01
3
08:56
5
05:57
3
08:11
2
11:55
5
11:55
2
06:07
7
13:30
6
