(;
GM[1]
SZ[19]
AW[dd][df][ci][co][dp][fp][po][pn][qn][pj][pi][qh][qg][pg][qf]
AB[ck][cn][dn][nq][pq][qp][qo][qd][pe][pf][og][oh][ph][fc][kc]
LB[ke:A][gf:B][ek:C]
C[Problem 136. Black to play.  

In this position, White has profit while Black has a moyo at the top. However, the black stones on the lower side are not very strong. How should Black continue ? ]
(;B[ke]
TE[2]
C[Correct Answer.  

Black should strengthen his position at the top with 1. ]
;W[ej]
C[White attacks with 2, but ... ]
;B[fn]
C[... Black simply jumps to 3 and, ... ]
;W[hp]
C[... after White 4, ... ]
;B[kq]
C[... Black 5 is a big extension, aiming to slide under White's position on the left. <= ]
)
(;B[ek]
C[Failure.  

Black strengthens his position with 1 and prepares to attack the top and bottom. ]
;W[ke]
C[But White wipes out Black's moyo with the sequence from 2 ... ]
;B[id];W[nf];B[of];W[lc]
C[... to 6. <= ]
)
(;B[gf]
C[Failure.  

If Black 1 here, White could easily invade this moyo. <= ]
)
)