what is the gfc for 20 and 30

10:13

2:41

2:31

2:07

3:49

4:46

13:05

13:05

3:56

10:33

8:35

1:04

12:55

1:32

9:10

9:10

16:54

16:54

21:03

6:48

4:26

5:00

32:12

31:22

5:15

25:36

2:20

4:55

12:19

20:16

6:47

11:17

5:05

10:22

18:15

6:22

2:26

11:11

11:10

4:25