(;GM[1]FF[4]SZ[19]
GN[Black to play]
PC[https://senseis.xmp.net/?IgoHatsuyoRonProblem104/Solution]AP[GoWiki:2009]
DT[2023-02-02]
C[Diagram from https://senseis.xmp.net/?IgoHatsuyoRonProblem104/Solution

Black to play]
PL[B]

AB[gb][lb][fc][lc][hd][ld][nd][qd][rd][le][me][ne][re][hf][jf][kf][qf][lg][pg]
AW[ib][kb][kc][nc][oc][rc][kd][md][ke][oe][pe][qe][lf][mf][nf][kg][og]
LB[na:a][nb:b]

;B[od]C[B1]MN[1]
;W[pd]C[W2]MN[2]
;B[pc]C[B3]MN[3]
;W[of]C[W4]MN[4]

;LB[na:a][nb:b]
)
