(;
GM[1]
SZ[19]
AW[dd][dg][cn][dp][jp][no][nq][nr][oe]
AB[oq][pp][pn][nm][qj][qd][oc][nd][id][fc]
LB[nd:2][oe:1]
C[Problem 156. White to play.  

When Black considers the top important, he will play 2. In that case, White will focus her attention on the right. Try to think a few moves ahead and give White a shape that is not heavy. ]
(;W[pd]
TE[2]
C[Correct Answer.  

White must first play 1, ... ]
;B[pc];W[qe]
C[... then 3. ]
;B[rd]
(;W[pi];B[qi];W[ph];B[pj];W[ni];B[oj];W[mf]
LB[qq:A]
C[Up to 11, White makes a fine sabaki. Black has solidified his lower right side, but there still remains a white invasion at A. <= ]
)
(;W[qh]
C[Failure.  

White 5 is heavy. ]
;B[oi]
TR[rd]
C[Black launches an attach with 2 and this stone, in concert with the marked stone, will make it hard for White to get sabaki. <= ]
))
(;W[qe]
LB[pd:@]
C[Failure.  

If you immediately attach with 1, neglecting to first play at @, ... ]
;B[pd]
C[... Black will play 2 himself, ... ]
;W[pe];B[mf]
C[... then jump out into the center with 4. White's three stones are heavy and almost without hope. <= ]
)
)