1

�

�

�

�

�

�

�

�

�

�

�

�

�

�

�

�

2

�

�

�

�

�

�

�

�

�

�

�

�

�

�

�

�

�

�

�

�

�

�

�

�

�

�

1

�

1

�

�

�