9 2 + 1 + 3+ +- 5 + 6 - 3 1 1 11 1 12 + + + 2 + + + 2 = 1- 2 +...

2

- 9

2

+ 1

+ 3

+

+

- 5

+ 6

- 3

2 -

1 1 1

1

1

1

2 + +

+ 2 +

+ + 2

= 1

- 2 + 2006

2

0

2

ˆ

0

ˆ ˆ

++

+

+

= 0

2

22