(;
GM[1]
SZ[19]
AW[dd][dj][dn][dp][jc][nc][ph][og][op][oq][pq][or][qp][rp][qq]
AB[pd][pf][pj][nh][fq][jp][pp][oo][po][qo][ro][np][nq][nr][mn]
LB[nh:A][og:B]
C[Problem 105. Black to play.  

Black A is not seen very often, but it is a valid move. How should Black continue after White B ? ]
;B[nd]
TE[2]
C[Correct Answer.  

Black 1 directly attacks the stone at the top and, from a distance, the two stones below. ]
;W[md];B[ne];W[oc];B[pc]
C[After the sequence to Black 5, ... ]
;W[ng]
C[... White pushes into the center with 6. ]
;B[mc]
C[Black now plays 7 ... ]
(;W[lc];B[mb]
C[... and 9. ]
;W[lb]
C[After White 10, ... ]
;B[ld]
C[... Black cuts with 11, ... ]
;W[me];B[mf]
C[... then ataris with 13. ]
;W[le];B[mg]
C[After Black 15, the three white stones on the right side are trapped. This leaning attack is similar to the one in Problem 48. <= ]
)
(;W[lg]
LB[lc:@]
C[Variation.  

Instead of @ in the Correct Answer, if White jumps to 8 here, ... ]
;B[ld];W[me];B[mf];W[le];B[mg]
C[... Black could play the sequence to 13 and trap the white stones on the right side. <= ]
)
(;W[mg]
C[Variation.  

If White 8 here, ... ]
;B[lc]
C[... Black secures the top with 9. <= ]
)
)