B1
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
|
B1
|
x
|
x
|
x
|
|
x
|
|
|
|
x
|
x
|
x
|
x
|
|
|||
|
|
|||||||
|
x
|
x
|
x
|
x
|
x
|
|
||
|
x
|
x
|
x
|
x
|
x
|
|
||