(;AW[ra]AW[ob]AW[rb]AW[pc]AW[qc]AW[sc]AW[qd]AW[rd]AW[pe]AW[of]AW[pf]AW[qf]AW[qg]AW[qh]AW[qi]AW[rj]AW[qk]AB[nb]AB[pb]AB[qb]AB[oc]AB[od]AB[pd]AB[oe]AB[qe]AB[re]AB[rf]AB[rg]AB[rh]AB[ri]AB[si]C[Black to play.]
(;B[sb]
(;W[sg]
(;B[sd];W[se]
(;B[sf];W[sj];B[sd];W[rc];B[oa]C[A two step ko for black. This is the best possible for black.RIGHT])
(;B[oa];W[sf]C[Black is dead.]))
(;B[se];W[sj]
(;B[sd];W[rc];B[oa];W[sf])
(;B[oa];W[sf]
(;B[sh];W[sf]C[Black dies.])
(;B[sd];W[sh])))
(;B[sf];W[sd]C[Black is dead.])
(;B[oa];W[sd]C[Black is dead.]))
(;W[sa];B[se]
(;W[sd];B[sg]C[This is not the hardest resistance from white. White can play like that if she dislikes the ko in the correct solution.])
(;W[sg];B[sd];W[rc];B[oa];W[sj];B[qa]C[This would be a big mistake by white.]))
(;W[sd];B[se];W[sa];B[sg]C[This is not the hardest resistance by white. But she can play like this if she wants to avoid the ko in the correct solution]))
(;B[se];W[sg]
(;B[sd];W[rc]
(;B[oa];W[sj];B[qa];W[sf])
(;B[sb];W[sj];B[oa];W[sf])
(;B[sa];W[sj];B[oa];W[sf]))
(;B[sb];W[sj]
(;B[sd];W[rc];B[oa];W[sf])
(;B[oa];W[sf]
(;B[sh];W[sf]C[Black is dead.])
(;B[qa]C[White has two eyes and black only one.])))
(;B[oa];W[sd]))
(;B[sg];W[se])
(;B[oa];W[sd])
(;B[sf];W[sd])
(;B[sd];W[se]C[Black is dead.]))
