(;GM[1]FF[4]SZ[19]
GN[O is on c]
PC[http://senseis.xmp.net/?CenterSearchAlgorithms]AP[GoWiki:2009]
DT[2009-04-22]
C[Diagram from http://senseis.xmp.net/?CenterSearchAlgorithms

O is on c]
PL[B]

AW[cc]
LB[aa:m][ba:n][ca:o][da:p][ab:l][bb:g][cb:f][db:i][ac:k][bc:f][dc:d][ad:j][bd:e][cd:b][dd:a]


;LB[aa:m][ba:n][ca:o][da:p][ab:l][bb:g][cb:f][db:i][ac:k][bc:f][dc:d][ad:j][bd:e][cd:b][dd:a]
)
