(;
GM[1]
SZ[19]
AW[bd][cd][dc][ed][qf][qj][qp][oq][ch][ci][di]
AB[gc][jc][nd][pd][jq][dp][ce][de][cg][dh][eh]
C[Problem 174. Black to play.  

In this position, the first thing you should focus on is the group of three white stones on the left side. How should Black attack them ? ]
(;B[cm]
TE[2]
C[Correct Answer.  

Black 1 is the ideal point to attack the white stones. ]
(;W[ei]
LB[cm:1]
C[In response to Black 1, White must run away with 2 ... ]
;B[fh];W[gj]
C[... and 4. ]
;B[hi]
C[While Black is chasing White, he is going to be building a moyo at the top and strengthening his stones in the lower left. <= ]
)
(;W[bg]
C[Variation.  

If White plays 2, ... ]
;B[be];W[dg];B[eg];W[cf];B[df]
LB[eb:B][fe:A]
C[... the sequence to Black 7 would follow. After this, confining White with Black A or sliding to Black B would be a severe attack on the white stones. <= ]
))
(;B[cn]
C[Failure.  

Black 1 leaves room ... ]
;W[cl]
C[... for a white extension to 2. <= ]
)
(;B[cl]
C[Failure.  

Black 1 would be too close to White's thick position above. <= ]
)
(;B[ei]
C[Failure.  

Black 1 ... ]
;W[ej];B[fj]
C[... and 3 are in the wrong direction. ]
;W[ek];B[cm]
C[Black must now extend to 5, but ... ]
;W[bl]
C[... White settles her stones with 6. <= ]
)
(;B[mq]
C[Failure.  

Black has to attack the white stones on the left. If he extends to 1 at the bottom right, ... ]
;W[cn]
C[... White will approach to 2 and ... ]
;B[fp];W[bp];B[cq];W[ei];B[fh];W[gj]
C[... her stones on the left side will be settled. <= ]
)
)