(;
GM[1]
SZ[19]
AW[bc][cc][dd][ed][gc][qj][oj][qn][pn][po][dp][cn][cj][dj]
AB[kc][od][qd][qh][qo][qp][pq][op][jp][fq][fo][ch][cd][ce][ef]
LB[eh:A][fo:B]
C[Problem 107. White to play.  

Instead of securing his stones at A, Black jumps to B. How should White attack the black stones on the left ? ]
;W[dg]
TE[2]
C[Correct Answer.  

White 1 is the vital point. ]
;B[cg]
C[If Black defends at 2, ... ]
;W[df]
C[... White plays 3 ... ]
;B[de];W[ee]
C[... and 5. and the black stones are in trouble. White is threatening to play A, but, if Black defends there, his stones will have a hard time making two eyes. <= ]
)
)