(;GM[1]FF[4]CA[UTF-8]AP[CGoban:3]ST[2]
RU[Japanese]SZ[19]KM[0.00]
GN[Cho L&D (abc)]AW[fb][fc][hc][dd][fd][be][ce][de][ch]AB[dc][ec][bd][cd]
(;B[bb]
;W[db]
;B[eb]
;W[ea]
(;B[cb]
;W[da]
(;B[ca]
;W[fa]
(;B[cc]
;W[ac]
;B[ad]
;W[ab]
;B[aa]
;W[ba]
;B[bc]C[+])
(;B[aa]C[+])
(;B[ad]
;W[cc]
;B[bc]
;W[ed]
(;B[ab]C[Black can live more efficiently])
(;B[aa]C[Black can live more efficiently])
(;B[cc]
;W[ab]
;B[aa]
;W[ba])))
(;B[cc]
;W[ac]
;B[ad]
;W[ab]
;B[ca]
;W[fa]
;B[aa]
;W[ba]
;B[bc]C[+]))
(;B[cc]
;W[ac]
;B[ad]
;W[ab]
(;B[ca]
;W[da]
(;B[cb]
;W[fa]
;B[aa]
;W[ba]
;B[bc]C[+])
(;B[aa]
;W[ba]
;B[cb]
;W[fa]
;B[bc]C[+]))
(;B[cb]
;W[da]
;B[ca]
;W[fa]
;B[aa]
;W[ba]
;B[bc]C[+])))
(;B[cb]
(;W[bc]
(;B[ab]
;W[cc]
(;B[bb]
;W[ad]
;B[eb]
;W[ea]
;B[da]
;W[fa]
;B[ba]C[+])
(;B[ad]
;W[db]
;B[eb]
;W[bb]
;B[ba]
;W[ca]
;B[ac]
;W[aa]))
(;B[bb]
;W[ad]
(;B[ab]
;W[cc]
;B[eb]
;W[ea]
;B[da]
;W[fa]
;B[ba]C[+])
(;B[cc]
;W[ab]))
(;B[cc]
;W[ab]
(;B[bb]
;W[ad]C[Wrong; advantageous ko.])
(;B[ad]
;W[da]
(;B[bb]
;W[ca])
(;B[ca]
;W[bb])))
(;B[ad]
;W[bb]
;B[ba]
;W[ab]
;B[cc]
;W[da])
(;B[ac]
;W[bb]
(;B[ba]
;W[ab]
;B[ad]
;W[da])
(;B[ab]
;W[ba]
(;B[cc]
;W[da])
(;B[eb]
;W[cc]))))
(;W[eb]
;B[ab]
;W[ba]
;B[db]
;W[bc]
;B[bb]
;W[ad]
;B[cc]))
(;B[bc]
;W[cb]
(;B[bb]
;W[db]
;B[eb]
;W[ea])
(;B[db]
;W[ad]
;B[bb]
;W[ac]
;B[ab]
;W[ba]
;B[ae]
;W[ad]))
(;B[cc]
;W[eb]
(;B[bb]
;W[ca])
(;B[db]
;W[bb]
;B[ab]
;W[ba]
(;B[ad])
(;B[da]
;W[ad])))
(;B[ab]
;W[cb]
;B[db]
;W[bb]))
