(;GM[1]FF[4]SZ[19]
GN[Black to play and connect underneath]
PC[https://senseis.xmp.net/?GokyoShumyoSection6Problem28/Solution]AP[GoWiki:2009]
DT[2023-01-24]
C[Diagram from https://senseis.xmp.net/?GokyoShumyoSection6Problem28/Solution

Black to play and connect underneath]
PL[B]

AB[cb][cc][hc][ic][dd][ee][he][ef][ff][cg]
AW[db][fc][jc][jd][fe][ge][gf][if][fg]
LB[gb:a][gc:c][fd:b]

;B[fb]C[B1]MN[1]
;W[eb]C[W2]MN[2]
;B[ec]C[B3]MN[3]

;LB[gb:a][gc:c][fd:b]
)
