(;
GM[1]
SZ[19]
AW[ic][kd][lc][nc]
AB[dd][gc][kc][ld][pc][pd][qg]
LB[lc:4][ld:3][kd:2][kc:1]
C[Problem 23. Black to play.  

Against Black's invasion, White attaches at 2 and cuts with 4. How should Black respond ? ]
(;B[jd]
TE[2]
C[Correct Answer.  

Black is strong on the right, so Black 1 ... ]
;W[ke];B[jc]
C[... and 3 are best. White's position on the right still has defects, but Black is strong on both sides. <= ]
)
(;B[mc]
TE[2]
C[Correct Answer.  

Black 1 ... ]
;W[lb];B[le]
C[... and 3 are a nice tesuji. ]
;W[mb];B[jd];W[kb];B[ke]
C[Black gets a nice ponnuki in the center of the board with the moves to 7. <= ]
)
)