(;AB[qa]AB[pb]AB[pc]AB[qc]AB[rc]AB[rd]AB[re]AB[se]AB[rf]AW[sf]AW[sg]AW[rg]AW[oc]AW[ob]AW[oa]AW[pa]AW[qf]C[Black to kill in ko. There is a sente seki, but that answer is insuffcient.]AW[pd]AB[qe]AW[qd]AW[pe]AW[pg]AP[goproblems]
(;W[rb]
(;B[sb]C[CHOICE]
(;W[sc]
(;B[ra]
(;W[sa]C[koRIGHT])
(;W[qd];B[qb]))
(;B[sa];W[ra]C[RIGHT]
(;B[qb];W[sb]C[RIGHT])
(;B[sb];W[qb]C[RIGHT]))
(;B[sd];W[ra]
(;B[qb];W[sc]C[RIGHT])
(;B[sa];W[sc]C[RIGHT]))
(;B[qb];W[sa]C[RIGHT]
(;B[ra];W[sb];B[sd];W[sb]C[RIGHT])
(;B[sd];W[sb];B[ra];W[sb]C[RIGHT])))
(;W[ra];B[qb];W[sc];B[sa])
(;W[qb];B[ra])
(;W[sa];B[ra])
(;W[qd];B[ra]))
(;B[sc];W[qb]
(;B[sb];W[ra]C[RIGHT])
(;B[ra];W[sa]
(;B[sb];W[qa]C[RIGHT])
(;B[ra];W[qa]C[RIGHT])
(;B[qa];W[ra];B[sb];W[qa]C[RIGHT]))
(;B[sa];W[ra];B[sb];W[qa]C[RIGHT]))
(;B[qb];W[sc]
(;B[ra];W[sb]C[RIGHT])
(;B[sb];W[sa]
(;B[ra];W[sb];B[sd];W[sb]C[RIGHT])
(;B[sd];W[sb];B[ra];W[sb]C[RIGHT]))
(;B[sa];W[sb]C[RIGHT])
(;B[sd];W[sb]C[RIGHT]))
(;B[ra]C[CHOICE]
(;W[sc];B[sb];W[sa]C[koRIGHT])
(;W[sb];B[sc]
(;W[qb];B[sa])
(;W[sa];B[qb]))
(;W[sa];B[qb]
(;W[sb];B[sc])
(;W[sc];B[sb]))
(;W[qb];B[sb]))
(;B[sa]
(;W[sc]
(;B[qb];W[sb]C[RIGHT])
(;B[ra];W[sb]C[RIGHT])
(;B[sb];W[ra]
(;B[qb];W[sb]C[RIGHT])
(;B[sb];W[qb]C[RIGHT]))
(;B[sd];W[sb]C[RIGHT]))
(;W[ra];B[qb]
(;W[sb];B[sc])
(;W[sc];B[sb]))
(;W[qb];B[sb]
(;W[sc];B[ra])
(;W[ra];B[qa]))
(;W[sb];B[sc]
(;W[qb];B[ra])
(;W[ra];B[qb])))
(;B[sd];W[ra]
(;B[qb];W[sb]C[RIGHT])
(;B[sb];W[qb]C[RIGHT])))
(;W[ra];B[qb]
(;W[rb];B[sb];W[sc];B[sa])
(;W[sb];B[sc])
(;W[sc];B[sb]))
(;W[qb];B[rb])
(;W[sb];B[ra]
(;W[sc];B[rb])
(;W[rb];B[sc]
(;W[qb];B[sa])
(;W[sa];B[qb])))
(;W[sc];B[rb])
(;W[qd];B[rb]))