1

1

1

1

1

1

1

1

1

1

�

�

2

�

2

�

�

2

�

�

�

1

1

1

1

1

1

1

1

1

1

1

1

�

�

�

�

�

�

�

�

�

l

l

�

�

�

�

�

�