(;
GM[1]
SZ[19]
AW[fc][jd][nc]
AB[dd][df][pd][pf]
C[Problem 26. Black to play.  

White's position is impressive but it is yet no territory. Where should Black invade ? ]
(;B[lc]
LB[hc:A]

TE[2]
C[Correct Answer.  

Black invades with 1. Since the position is symmetrical, he could just as well have invaded at A. ]
;W[md];B[hc];W[gd]
LB[md:2]
C[If White responds with the diagonal moves at 2 and 4, ... ]
;B[jc]
C[... Black attaches at 5. Black is firmly established at the top. <= ]
)
(;B[hc]
TE[2]
C[Correct Answer.  

Also correct. <= ]
)
)