(;
GM[1]
SZ[19]
AW[jd][nd][oc][pc][nf]
AB[dd][hc][ld][qc][qd][pd][pf]
LB[nf:1]
C[Problem 18. Black to play.  

White jumps to 1. What is Black's strongest move ? ]
(;B[kd]
TE[2]
C[Correct Answer.  

Black should bump against the white stone with 1 and ... ]
;W[je];B[lf]
C[... then jump to 3. This is the strongest counter. <= ]
)
(;B[lf]
C[Failure.  

If Black simply jumps to 1, ... ]
;W[lc]
C[... White attaches with 2 and ... ]
;B[kc];W[kd];B[mc];W[le];B[lb];W[md]
C[... links up her stones with the moves to 8. <= ]
)
)