(;
GM[1]
SZ[19]
AW[cc][db][cd][je][pc][qe]
AB[dc][dd][eb][ce][df][cj][hd][jc]
LB[eb:4][db:3][ce:2][cd:1]
C[Problem 116. White to play.  

After Black 4, White can't live unconditionally. Where does White play to get a ko ? ]
;W[bb]
TE[2]
C[Correct Answer.  

The only move for White is 1. ]
(;B[da]
C[After Black 2, ... ]
;W[ca]
C[... White must pin her hopes on a ko by playing 3. <= ]
)
(;B[bd]
C[Failure.  

If Black 2, ... ]
;W[bc];B[be];W[ca]
LB[bc:3]
C[... White can live unconditionally with 3 and 5. <= ]
)
)