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L19 Go Problem Championship: Round 12

Posted: Sun May 07, 2017 10:06 pm
by Kirby
Welcome to Round 12 of the L19 Go Problem Championship.

All problems are black to play. As usual, provide your solutions either via hide tags, or direct private message to me.

Problem 1 (3 points)
Click Here To Show Diagram Code
[go]$$Bc
$$ --------------
$$ | X O . O X . .
$$ | X . X X X O .
$$ | . . O O O O .
$$ | O O . , . . .
$$ | . . . . . . .[/go]
Problem 2 (6 points)
Click Here To Show Diagram Code
[go]$$Bc
$$ ---------------------------
$$ | . . . . . . . . . . . . . |
$$ | . . . . . . . . O X . . . |
$$ | . O . O O . . O X O . . . |
$$ | . . O X . . , . X X X . . |
$$ | . O X . X . . . . . . . . |
$$ | . O X . . . . . . . . . . |
$$ | . X Q Q . . , . . , O . . |
$$ | . X X Q . . . . . X X O . |
$$ | . X O X X . . . . . . O . |
$$ | . O O X . . , X O O . . . |
$$ | . . O X O X . X X X O . . |
$$ | . . O O X . X . . . O . . |
$$ | . . . . . X . . . . . . . |
$$ ---------------------------[/go]
Problem 3 (9 points)
Click Here To Show Diagram Code
[go]$$Bc
$$ | . . . . . . . . . . .
$$ | . . X X X X . . . . .
$$ | . X . O O . X . . . .
$$ | . X O X O . O X . , .
$$ | . X . . . . . X . . .
$$ | . X O . . O O X . X .
$$ | . O . . . . . . . . .
$$ ----------------------[/go]
Have fun! :salute:

Posted: Sun May 07, 2017 11:00 pm
by EdLee
Click Here To Show Diagram Code
[go]$$B Life
$$ -------------------
$$ | X O . O X . . . .
$$ | X 1 X X X O . O .
$$ | . . O O O O . . .
$$ | O O O , . . . . .
$$ | . . . . . . . . .[/go]
Click Here To Show Diagram Code
[go]$$B
$$ ------------------
$$ | X O 1 O X . . . .
$$ | X 2 X X X O . O .
$$ | . 3 O O O O . . .
$$ | O O O , . . . . .
$$ | . . . . . . . . .[/go]
Click Here To Show Diagram Code
[go]$$B Connect-and-die
$$ ------------------
$$ | X . X . X . . . .
$$ | X 4 X X X O . O .
$$ | . X O O O O . . .
$$ | O O O , . . . . .
$$ | . . . . . . . . .[/go]
Click Here To Show Diagram Code
[go]$$B
$$ ------------------
$$ | X 5 X . X . . . .
$$ | X . X X X O . O .
$$ | 6 X O O O O . . .
$$ | O O O , . . . . .
$$ | . . . . . . . . .[/go]
:study:

:study:
Click Here To Show Diagram Code
[go]$$B
$$ | . . . . . . . . . . .
$$ | . . X X X X . . . . .
$$ | . X . O O . X . . . .
$$ | . X O X O . O X . , .
$$ | . X . 1 . . . X . . .
$$ | . X O . . O O X . X .
$$ | . O . . . . . . . . .
$$ -----------------------[/go]

Re: L19 Go Problem Championship: Round 12

Posted: Mon May 08, 2017 2:20 am
by fractic
I'm not sure you can even capture the marked stones in problem 2.
Click Here To Show Diagram Code
[go]$$Bc
$$ ---------------------------
$$ | . . . . . . . . . . . . . |
$$ | . . . . . . . . O X . . . |
$$ | . O . O O . . O X O . . . |
$$ | . . O X . . , . X X X . . |
$$ | . O X 8 X . . . . . . . . |
$$ | . O X . 2 3 . . . . . . . |
$$ | . X Q Q 1 6 7 . . , O . . |
$$ | . X X Q 4 5 . . . X X O . |
$$ | . X O X X . . . . . . O . |
$$ | . O O X . . , X O O . . . |
$$ | . . O X O X . X X X O . . |
$$ | . . O O X . X . . . O . . |
$$ | . . . . . X . . . . . . . |
$$ ---------------------------[/go]
Click Here To Show Diagram Code
[go]$$Bc
$$ ---------------------------
$$ | . . . . . . . . . . . . . |
$$ | . . . . . . . . O X . . . |
$$ | . O . O O . . O X O . . . |
$$ | . . O X . . , . X X X . . |
$$ | . O X . X . . . . . . . . |
$$ | . O X . 2 3 . . . . . . . |
$$ | . X Q Q 1 5 . . . , O . . |
$$ | . X X Q 4 8 . . . X X O . |
$$ | . X O X X 6 . . . . . O . |
$$ | . O O X 7 . , X O O . . . |
$$ | . . O X O X . X X X O . . |
$$ | . . O O X . X . . . O . . |
$$ | . . . . . X . . . . . . . |
$$ ---------------------------[/go]
Click Here To Show Diagram Code
[go]$$Bc
$$ ---------------------------
$$ | . . . . . . . . . . . . . |
$$ | . . . . . . . . O X . . . |
$$ | . O . O O . . O X O . . . |
$$ | . . O X . . , . X X X . . |
$$ | . O X 5 X 7 . . . . . . . |
$$ | . O X 4 2 6 8 . . . . . . |
$$ | . X Q Q 1 . . . . , O . . |
$$ | . X X Q 3 . . . . X X O . |
$$ | . X O X X . . . . . . O . |
$$ | . O O X 7 . , X O O . . . |
$$ | . . O X O X . X X X O . . |
$$ | . . O O X . X . . . O . . |
$$ | . . . . . X . . . . . . . |
$$ ---------------------------[/go]
Click Here To Show Diagram Code
[go]$$Bc
$$ ---------------------------
$$ | . . . . . . . . . . . . . |
$$ | . . . . . . . . O X . . . |
$$ | . O . O O . . O X O . . . |
$$ | . . O X . . , . X X X . . |
$$ | . O X 3 X . . . . . . . . |
$$ | . O X . 2 4 . . . . . . . |
$$ | . X Q Q . . . . . , O . . |
$$ | . X X Q 1 . . . . X X O . |
$$ | . X O X X . . . . . . O . |
$$ | . O O X . . , X O O . . . |
$$ | . . O X O X . X X X O . . |
$$ | . . O O X . X . . . O . . |
$$ | . . . . . X . . . . . . . |
$$ ---------------------------[/go]

Re: L19 Go Problem Championship: Round 12

Posted: Mon May 08, 2017 4:09 am
by Cassandra
@ fractic:
Click Here To Show Diagram Code
[go]$$Bc
$$ ---------------------------
$$ | . . . . . . . . . . . . . |
$$ | . . . . . . . . O X . . . |
$$ | . O . O O . . O X O . . . |
$$ | . . O X . . , . X X X . . |
$$ | . O X 3 X . . . . . . . . |
$$ | . O X . 2 . . . . . . . . |
$$ | . X Q Q 1 . . . . , O . . |
$$ | . X X Q . . . . . X X O . |
$$ | . X O X X . . . . . . O . |
$$ | . O O X . . , X O O . . . |
$$ | . . O X O X . X X X O . . |
$$ | . . O O X . X . . . O . . |
$$ | . . . . . X . . . . . . . |
$$ ---------------------------[/go]
Did you ever consider Black's resistance with 3 here ?

The solution sequence will become longish ;-)

Re: L19 Go Problem Championship: Round 12

Posted: Mon May 08, 2017 4:51 am
by fractic
@ Cassandra
I did consider that move. I just didn't read out the ladder correctly.

Re: L19 Go Problem Championship: Round 12

Posted: Mon May 08, 2017 7:08 am
by Kirby
@EdLee:
If white resists?
Click Here To Show Diagram Code
[go]$$Bc
$$ ---------------------------
$$ | . . . . . . . . . . . . . |
$$ | . . . . . . . . O X . . . |
$$ | . O . O O . . O X O . . . |
$$ | . . O X . . , . X X X . . |
$$ | . O X . X . . . . . . . . |
$$ | . O X . 2 . . . . . . . . |
$$ | . X O O 1 . . . . , O . . |
$$ | . X X O . . . . . X X O . |
$$ | . X O X X . . . . . . O . |
$$ | . O O X . . , X O O . . . |
$$ | . . O X O X . X X X O . . |
$$ | . . O O X . X . . . O . . |
$$ | . . . . . X . . . . . . . |
$$ ---------------------------[/go]

Re: L19 Go Problem Championship: Round 12

Posted: Mon May 08, 2017 7:32 am
by Schachus
After some break, I decided to have a look at this again:
Kirby wrote:Welcome to Round 12 of the L19 Go Problem Championship.

All problems are black to play. As usual, provide your solutions either via hide tags, or direct private message to me.

Problem 1 (3 points)
Click Here To Show Diagram Code
[go]$$Bc
$$ --------------
$$ | X O . O X . .
$$ | X . X X X O .
$$ | . . O O O O .
$$ | O O . , . . .
$$ | . . . . . . .[/go]
Click Here To Show Diagram Code
[go]$$Bc
$$ --------------
$$ | X O . O X . .
$$ | X 1 X X X O .
$$ | . . O O O O .
$$ | O O . , . . .
$$ | . . . . . . .[/go]
nothing much to say...
Problem 2 (6 points)
Click Here To Show Diagram Code
[go]$$Bc
$$ ---------------------------
$$ | . . . . . . . . . . . . . |
$$ | . . . . . . . . O X . . . |
$$ | . O . O O . . O X O . . . |
$$ | . . O X . . , . X X X . . |
$$ | . O X . X . . . . . . . . |
$$ | . O X . . . . . . . . . . |
$$ | . X Q Q . . , . . , O . . |
$$ | . X X Q . . . . . X X O . |
$$ | . X O X X . . . . . . O . |
$$ | . O O X . . , X O O . . . |
$$ | . . O X O X . X X X O . . |
$$ | . . O O X . X . . . O . . |
$$ | . . . . . X . . . . . . . |
$$ ---------------------------[/go]
seems like a one way street:
Click Here To Show Diagram Code
[go]$$Bc
$$ ---------------------------
$$ | . . . . . . . . . . . . . |
$$ | . . . . . . . . O X . . . |
$$ | . O . O O . . O X O . . . |
$$ | . . O X . . , . X X X . . |
$$ | . O X 3 X . . . . . . . . |
$$ | . O X 7 2 . . . . . . . . |
$$ | . X Q Q 1 6 9 . . , O . . |
$$ | . X X Q 4 5 . . . X X O . |
$$ | . X O X X . . . . . . O . |
$$ | . O O X . . , X O O . . . |
$$ | . . O X O X . X X X O . . |
$$ | . . O O X . X . . . O . . |
$$ | . . . . . X . . . . . . . |
$$ ---------------------------[/go]
(8 connects at 1) and the ladder works:
Click Here To Show Diagram Code
[go]$$Wc
$$ ---------------------------
$$ | . . . . . . . . . . . . . |
$$ | . . . . . . . . O X . . . |
$$ | . O . O O . . O X O . . . |
$$ | . . O X . . 6 8 X X X . . |
$$ | . O X X X 2 5 7 9 . . . . |
$$ | . O X X O 1 3 4 . . . . . |
$$ | . X O O O O X . . , O . . |
$$ | . X X O O X . . . X X O . |
$$ | . X O X X . . . . . . O . |
$$ | . O O X . . , X O O . . . |
$$ | . . O X O X . X X X O . . |
$$ | . . O O X . X . . . O . . |
$$ | . . . . . X . . . . . . . |
$$ ---------------------------[/go]
and another continuation(how do 1 get more than 9 moves in one diagram??):
Click Here To Show Diagram Code
[go]$$Bc
$$ ---------------------------
$$ | . . . . . . . . . . . . . |
$$ | . . . . . . . . O X . . . |
$$ | . O . O O . . O X O . . . |
$$ | . . O X . . X X X X X . . |
$$ | . O X X X X O O O 2 3 . . |
$$ | . O X X O O O X 1 4 5 . . |
$$ | . X O O O O X 9 8 6 O 7 . |
$$ | . X X O O X . . . X X O . |
$$ | . X O X X . . . . . . O . |
$$ | . O O X . . , X O O . . . |
$$ | . . O X O X . X X X O . . |
$$ | . . O O X . X . . . O . . |
$$ | . . . . . X . . . . . . . |
$$ ---------------------------[/go]
there is 3 more moves, but I think you can see the ladder works from here :)

Re: L19 Go Problem Championship: Round 12

Posted: Mon May 08, 2017 9:16 am
by Kirby
@Schachus
You've got it!

Re: L19 Go Problem Championship: Round 12

Posted: Mon May 08, 2017 9:47 am
by hyperpape
Problem 1
Click Here To Show Diagram Code
[go]$$Bc
$$ --------------
$$ | X O . O X . .
$$ | X 1 X X X O .
$$ | . . O O O O .
$$ | O O . , . . .
$$ | . . . . . . .[/go]
Problem 2
This is a bit harder.
Click Here To Show Diagram Code
[go]$$Bc
$$ ---------------------------
$$ | . . . . . . . . . . . . . |
$$ | . . . . . . . . O X . . . |
$$ | . O . O O . . O X O . . . |
$$ | . . O X . . , . X X X . . |
$$ | . O X . X . . . . . . . . |
$$ | . O X . 2 3 . . . . . . . |
$$ | . X Q Q 1 5 , . . , O . . |
$$ | . X X Q 4 . . . . X X O . |
$$ | . X O X X 6 . . . . . O . |
$$ | . O O X 7 8 , X O O . . . |
$$ | . . O X O X . X X X O . . |
$$ | . . O O X . X . . . O . . |
$$ | . . . . . X . . . . . . . |
$$ ---------------------------[/go]
Click Here To Show Diagram Code
[go]$$Wc Shenanigans!
$$ ---------------------------
$$ | . . . . . . . . . . . . . |
$$ | . . . . . . . . O X . . . |
$$ | . O . O O . . O X O . . . |
$$ | . . O X . . , . X X X . . |
$$ | . O X . X 2 . . . . . . . |
$$ | . O X . W X . . . . . . . |
$$ | . X Q Q X X , . . 7 O . . |
$$ | . X X Q W 1 . . 5 X X O . |
$$ | . X O X X W . 3 4 6 . O . |
$$ | . O O X X W , X O O 8 . . |
$$ | . . O X X X . X X X O . . |
$$ | . . O O X . X . . . O . . |
$$ | . . . . . X . . . . . . . |
$$ ---------------------------[/go]
Click Here To Show Diagram Code
[go]$$Bc hopefully good enough for B?
$$ ---------------------------
$$ | . . . . . . . . . . . . . |
$$ | . . . . . . . . O X . . . |
$$ | . O . O O . . O X O . . . |
$$ | . . O X . . , . X X X . . |
$$ | . O X . X . . . . . . . . |
$$ | . O X 5 2 3 . . . . . . . |
$$ | . X Q Q 1 . , . . , O . . |
$$ | . X X Q 4 6 . 7 . X X O . |
$$ | . X O X X . . . . . . O . |
$$ | . O O X . . , X O O . . . |
$$ | . . O X O X . X X X O . . |
$$ | . . O O X . X . . . O . . |
$$ | . . . . . X . . . . . . . |
$$ ---------------------------[/go]

Re: L19 Go Problem Championship: Round 12

Posted: Mon May 08, 2017 10:07 am
by gamesorry
1.
Click Here To Show Diagram Code
[go]$$Bc
$$ --------------
$$ | X O . O X . .
$$ | X 1 X X X O .
$$ | . . O O O O .
$$ | O O . , . . .
$$ | . . . . . . .[/go]
2.
B3 is the key move
Click Here To Show Diagram Code
[go]$$Bc
$$ ---------------------------
$$ | . . . . . . . . . . . . . |
$$ | . . . . . . . . O X . . . |
$$ | . O . O O . . O X O . . . |
$$ | . . O X . . , . X X X . . |
$$ | . O X 3 X . . . . . . . . |
$$ | . O X . 2 . . . . . . . . |
$$ | . X Q Q 1 6 , . . , O . . |
$$ | . X X Q 4 5 . . . X X O . |
$$ | . X O X X . . . . . . O . |
$$ | . O O X . . , X O O . . . |
$$ | . . O X O X . X X X O . . |
$$ | . . O O X . X . . . O . . |
$$ | . . . . . X . . . . . . . |
$$ ---------------------------[/go]
Click Here To Show Diagram Code
[go]$$Bc
$$ ---------------------------
$$ | . . . . . . . . . . . . . |
$$ | . . . . . . . . O X . . . |
$$ | . O . O O . . O X O . . . |
$$ | . . O X . . 9 a X X X . . |
$$ | . O X X X 5 8 0 b d e . . |
$$ | . O X 1 O 4 6 7 c f g . . |
$$ | . X Q Q 2 O 3 k j h O i . |
$$ | . X X Q O X o n l X X O . |
$$ | . X O X X . . . m . . O . |
$$ | . O O X . . , X O O . . . |
$$ | . . O X O X . X X X O . . |
$$ | . . O O X . X . . . O . . |
$$ | . . . . . X . . . . . . . |
$$ ---------------------------[/go]

Re: L19 Go Problem Championship: Round 12

Posted: Mon May 08, 2017 10:13 am
by Kirby
@hyperpape:
Click Here To Show Diagram Code
[go]$$Bc hopefully good enough for B?
$$ ---------------------------
$$ | . . . . . . . . . . . . . |
$$ | . . . . . . . . O X . . . |
$$ | . O . O O . . O X O . . . |
$$ | . . O X . . , . X X X . . |
$$ | . O X . X . . . . . . . . |
$$ | . O X 5 2 3 . . . . . . . |
$$ | . X Q Q 1 . , . . , O . . |
$$ | . X X Q 4 6 . 7 . X X O . |
$$ | 8 X O X X . . . . . . O . |
$$ | . O O X . . , X O O . . . |
$$ | . . O X O X . X X X O . . |
$$ | . . O O X . X . . . O . . |
$$ | . . . . . X . . . . . . . |
$$ ---------------------------[/go]
Maybe consider an alternate move for :b3:?

Re: L19 Go Problem Championship: Round 12

Posted: Mon May 08, 2017 10:14 am
by Kirby
@gamesorry:
Yep.

Re: L19 Go Problem Championship: Round 12

Posted: Tue May 09, 2017 6:37 am
by hyperpape
Wow, what a case of tunnel vision. When I plan the first move, I know the issue is reducing White's liberties, but I got so caught up in proving White can't escape that I forgot it.

Anyway, I still can't see an answer. I'll have to keep looking.
Click Here To Show Diagram Code
[go]$$
$$ ---------------------------
$$ | . . . . . . . . . . . . . |
$$ | . . . . . . . . O X . . . |
$$ | . O . O O . . O X O . . . |
$$ | . . O X . . , . X X X . . |
$$ | . O X 5 X . . . . . . . . |
$$ | . O X 4 2 6 . . . . . . . |
$$ | . X Q Q 1 . , . . , O . . |
$$ | . X X Q 3 . . . . X X O . |
$$ | . X O X X . . . . . . O . |
$$ | . O O X . . , X O O . . . |
$$ | . . O X O X . X X X O . . |
$$ | . . O O X . X . . . O . . |
$$ | . . . . . X . . . . . . . |
$$ ---------------------------[/go]
Click Here To Show Diagram Code
[go]$$
$$ ---------------------------
$$ | . . . . . . . . . . . . . |
$$ | . . . . . . . . O X . . . |
$$ | . O . O O . . O X O . . . |
$$ | . . O X . . , . X X X . . |
$$ | . O X 4 X . . . . . . . . |
$$ | . O X . 2 . . . . . . . . |
$$ | . X Q Q 1 3 , . . , O . . |
$$ | . X X Q . . . . . X X O . |
$$ | . X O X X . . . . . . O . |
$$ | . O O X . . , X O O . . . |
$$ | . . O X O X . X X X O . . |
$$ | . . O O X . X . . . O . . |
$$ | . . . . . X . . . . . . . |
$$ ---------------------------[/go]

Re: L19 Go Problem Championship: Round 12

Posted: Tue May 09, 2017 8:56 am
by Kirby
@hyperpape:

Hint: (look if you want it)
After :w2:, this weak point is pretty annoying - it keeps posing a problem...
Click Here To Show Diagram Code
[go]$$
$$ ---------------------------
$$ | . . . . . . . . . . . . . |
$$ | . . . . . . . . O X . . . |
$$ | . O . O O . . O X O . . . |
$$ | . . O X . . , . X X X . . |
$$ | . O X C X . . . . . . . . |
$$ | . O X . 2 . . . . . . . . |
$$ | . X O O 1 . , . . , O . . |
$$ | . X X O . . . . . X X O . |
$$ | . X O X X . . . . . . O . |
$$ | . O O X . . , X O O . . . |
$$ | . . O X O X . X X X O . . |
$$ | . . O O X . X . . . O . . |
$$ | . . . . . X . . . . . . . |
$$ ---------------------------[/go]

Re: L19 Go Problem Championship: Round 12

Posted: Tue May 09, 2017 6:04 pm
by jeromie
I haven't tried to solve these problems in a while.

Problem 1 (3 points)
This seems so easy I feel like I might be missing something. :-)
Click Here To Show Diagram Code
[go]$$Bc
$$ --------------
$$ | X O . O X . .
$$ | X 1 X X X O .
$$ | . . O O O O .
$$ | O O . , . . .
$$ | . . . . . . .[/go]
Problem 2 (6 points)
This one is fun!
Click Here To Show Diagram Code
[go]$$Bc
$$ ---------------------------
$$ | . . . . . . . . . . . . . |
$$ | . . . . . . . . O X . . . |
$$ | . O . O O . . O X O . . . |
$$ | . . O X . . , . X X X . . |
$$ | . O X 3 X . . . . . . . . |
$$ | . O X . 2 . . . . . . . . |
$$ | . X Q Q 1 . , . . , O . . |
$$ | . X X Q . . . . . X X O . |
$$ | . X O X X . . . . . . O . |
$$ | . O O X . . , X O O . . . |
$$ | . . O X O X . X X X O . . |
$$ | . . O O X . X . . . O . . |
$$ | . . . . . X . . . . . . . |
$$ ---------------------------[/go]
If white resists, this gets long...
Click Here To Show Diagram Code
[go]$$Bc
$$ ---------------------------
$$ | . . . . . . . . . . . . . |
$$ | . . . . . . . . O X . . . |
$$ | . O . O O . . O X O . . . |
$$ | . . O X . . , . X X X . . |
$$ | . O X 3 X . . . . . . . . |
$$ | . O X 7 2 . . . . . . . . |
$$ | . X Q Q 1 6 , . . , O . . |
$$ | . X X Q 4 5 . . . X X O . |
$$ | . X O X X . . . . . . O . |
$$ | . O O X . . , X O O . . . |
$$ | . . O X O X . X X X O . . |
$$ | . . O O X . X . . . O . . |
$$ | . . . . . X . . . . . . . |
$$ ---------------------------[/go]
Click Here To Show Diagram Code
[go]$$Wc
$$ ---------------------------
$$ | . . . . . . . . . . . . . |
$$ | . . . . . . . . O X . . . |
$$ | . O . O O . . O X O . . . |
$$ | . . O X . . 8 0 X X X . . |
$$ | . O X X X 4 7 9 . . . . . |
$$ | . O X X O 3 5 6 . . . . . |
$$ | . X Q Q 1 O 2 . . , O . . |
$$ | . X X Q O X . . . X X O . |
$$ | . X O X X . . . . . . O . |
$$ | . O O X . . , X O O . . . |
$$ | . . O X O X . X X X O . . |
$$ | . . O O X . X . . . O . . |
$$ | . . . . . X . . . . . . . |
$$ ---------------------------[/go]
Click Here To Show Diagram Code
[go]$$B
$$ +---------------------------+
$$ | . . . . . . . . . . . . . |
$$ | . . . . . . . . O X . . . |
$$ | . O . O O . . O X O . . . |
$$ | . . O X . . X 1 X X X . . |
$$ | . O X X X X O O 2 4 5 . . |
$$ | . O X X O O O X 3 6 7 . . |
$$ | . X O O O O X . 0 8 O 9 . |
$$ | . X X O O X . . . X X O . |
$$ | . X O X X . . . . . . O . |
$$ | . O O X . . . X O O . . . |
$$ | . . O X O X . X X X O . . |
$$ | . . O O X . X . . . O . . |
$$ | . . . . . X . . . . . . . |
$$ +---------------------------+[/go]
Click Here To Show Diagram Code
[go]$$B
$$ +---------------------------+
$$ | . . . . . . . . . . . . . |
$$ | . . . . . . . . O X . . . |
$$ | . O . O O . . O X O . . . |
$$ | . . O X . . X X X X X . . |
$$ | . O X X X X O O O O X . . |
$$ | . O X X O O O X X O X . . |
$$ | . X O O O O X 1 O O O X . |
$$ | . X X O O X 5 4 2 X X O . |
$$ | . X O X X . 7 6 3 . . O . |
$$ | . O O X . . . X O O . . . |
$$ | . . O X O X . X X X O . . |
$$ | . . O O X . X . . . O . . |
$$ | . . . . . X . . . . . . . |
$$ +---------------------------+[/go]