b2 up b2
2
b2 up 2
b3
b2 up b3
3
b2 up 3
4
b2 up 4
b5
b2 up b5
5
b2 up 5
b6
b2 up b6
6
b2 up 6
b7
b2 up b7
7
b2 up 7
1
b2 down b2
1
b2 down 2
7
b2 down b3
b7
b2 down 3
6
b2 down 4
b6
b2 down b5
5
b2 down 5
b5
b2 down b6
4
b2 down 6
3
b2 down b7
b3
b2 down 7
2