(;
GM[1]
SZ[19]
AW[kc][od][qd][bd][cf][ci]
AB[cc][dd][fd][ic]
C[Problem 111. Black to play.  

White's extension is one space narrower than in Problem 108. Where should Black invade ? ]
(;B[mc]
TE[2]
C[Correct Answer.  

Black 1 is the vital point. We will look at the variations in the next few problems. <= ]
)
(;B[pc]
LB[mc:@]

TE[2]
C[Correct Answer.  

Black could also peep at 1. However, Black @ in the Correct Answer is the usual move. <= ]
)
(;B[lc]
TE[2]
C[Correct Answer.  

Attaching at Black 1 is also possible. <= ]
)
)