(;GM[1]FF[4]SZ[19]
GN[Black's second-order mistake]
PC[http://senseis.xmp.net/?ShapeProblem6/OneWayStreet]AP[GoWiki:2009]
DT[2009-04-22]
C[Diagram from http://senseis.xmp.net/?ShapeProblem6/OneWayStreet

Black's second-order mistake]
PL[B]

AB[db][eb][gb][dc][ec][fc][bd][cd][ed][fd][be][ge][bf][cf][bg][ch]
AW[da][ea][fa][cb][fb][cc][gc][dd][ce][de][ee][he][df][gf][cg]
CR[fa][gb][ge][gf]
LB[ic:c][fe:b][ie:d][ff:a]

;B[hd]C[B1]MN[1]
;W[hc]C[W2]MN[2]

;CR[fa][gb][ge][gf]
LB[ic:c][fe:b][ie:d][ff:a]
)
