(;SZ[19]AW[gb]AW[kb]AW[fc]AW[jc]AW[kc]AW[nc]AW[dd]AW[jd]AW[ld]AW[md]AW[nd]AW[nf]AB[ib]AB[lb]AB[nb]AB[lc]AB[mc]AB[oc]AB[hd]AB[id]AB[kd]AB[pd]AB[je]AB[ke]AB[if]TR[kb]TR[jc]TR[kc]TR[jd]C[white to save the marked stones in the best way. ko is to be avoided.]GM[1]FF[4]CA[UTF-8]AP[CGoban:2]RU[Japanese]KM[0.00]TM[]PL[W]
(;W[ka]
(;B[mb]
(;W[ha];B[ia]
(;W[ic];B[hc];W[hb]C[
seki (if black plays another move)RIGHT])
(;W[hc];B[ic])
(;W[hb];B[ic]))
(;W[ic];B[hc]
(;W[hb];B[ja])
(;W[ha];B[ja])
(;W[ia];B[ha];W[hb];B[ja]))
(;W[hb]
(;B[ic];W[ia];B[ja];W[jb];B[la])
(;B[ja]
(;W[jb];B[ic];W[ia];B[la])
(;W[ic];B[hc])))
(;W[ia];B[ha]
(;W[hb];B[ja]
(;W[jb];B[ic]C[ko])
(;W[ic];B[hc]))
(;W[ic];B[hc];W[hb];B[ja])
(;W[ja];B[hb])))
(;B[la];W[ma];B[mb];W[ob];B[na];W[oa]))
(;W[mb];B[ma]
(;W[ka];B[la]
(;W[ha];B[ia];W[ic];B[hc];W[hb]C[gote seki, not best])
(;W[ia];B[ha];W[ic];B[hc];W[hb];B[ja])
(;W[ic];B[hc];W[ha];B[hb]))
(;W[ja];B[la]
(;W[ia];B[ha]
(;W[hb];B[ic])
(;W[ic];B[hc];W[hb];B[ka]))
(;W[ic];B[hc];W[ha];B[hb])
(;W[ha];B[jb]
(;W[ia];B[ka])
(;W[ic];B[hc])))
(;W[ic];B[hc]
(;W[ha];B[ka])
(;W[jb];B[ja]))
(;W[ia];B[ha]
(;W[hb];B[ja];W[ic];B[hc])
(;W[ic];B[hc];W[hb];B[ja]))
(;W[ha];B[ia];W[ic];B[hc];W[hb];B[ka]))
(;W[ic];B[hc]
(;W[ka];B[ja]
(;W[mb];B[ma])
(;W[la];B[mb]
(;W[ob];B[jb])
(;W[hb];B[ma]))
(;W[hb];B[la]))
(;W[la];B[mb];W[hb];B[jb])
(;W[ja];B[jb])
(;W[hb];B[ka]))
(;W[ia];B[ha]
(;W[hb];B[ja];W[ic];B[hc])
(;W[ic];B[hc];W[hb];B[ja])
(;W[ja];B[hb]))
(;W[ob];B[pb]C[this exchange doesn't help white])
(;W[la];B[mb]
(;W[ha];B[jb]
(;W[ic];B[hc])
(;W[ja];B[ic]))
(;W[ic];B[hc];W[hb];B[jb])
(;W[ob];B[pb]))
(;W[ja]
(;B[jb]
(;W[mb];B[ma];W[la];B[ka]C[2-step ko])
(;W[ka];B[ic];W[mb];B[ma])
(;W[la];B[mb];W[ob];B[ic]))
(;B[la]
(;W[ia];B[ha]
(;W[hb];B[ic];W[ga];B[jb])
(;W[ic];B[hc];W[hb];B[ka]))
(;W[ob];B[pb])
(;W[ma])))
(;W[hc];B[ic])
(;W[ha]
(;B[ia];W[ic];B[hc]
(;W[hb];B[ka])
(;W[la];B[mb];W[hb]))
(;B[jb]
(;W[ja];B[ic])
(;W[la];B[mb];W[ja];B[ic])
(;W[ic];B[hc])
(;W[ka];B[ic];W[mb];B[ma])))
(;W[jb];B[ic])
(;W[hb];B[jb];W[ka];B[ic])
(;W[ma];B[mb]
(;W[ob];B[pb])
(;W[la];B[ob];W[ha];B[jb])))