(;GM[1]FF[4]SZ[19]
GN[Observation (W5 at W1)]
PC[http://senseis.xmp.net/?RTGProblem66/Solution]AP[GoWiki:2009]
DT[2009-11-10]
C[Diagram from http://senseis.xmp.net/?RTGProblem66/Solution

Observation (W5 at W1)]
PL[W]

AB[bk][ik][cl][el][gl][il][bm][cm][em][fm][gm][hm][an][cn][fn][in][jn][go][ho][hp][ip][bq][fq][gq][ar][cr][dr][gr][hr][ir][bs][fs][js]
AW[bj][cj][ck][ek][fk][gk][hk][al][bl][fl][hl][bn][dn][en][bo][eo][io][jo][bp][cp][fp][gp][jp][cq][dq][eq][iq][kq][er][fr][jr][kr][ds][gs][is]

;W[aq]C[W1]MN[1]
;B[ap]C[B2]MN[2]
;W[ao]C[W3]MN[3]
;B[am]C[B4]MN[4]
;W[aq]C[W5]MN[5]

;
)
