(;AW[ar]AW[cs]AW[bp]AW[cp]AW[dp]AW[ep]AW[fp]AW[gp]AW[gq]AW[gr]AW[gs]AW[fs]AB[dr]AB[dq]AB[eq]AB[fq]AB[fr]AB[es]AB[cq]AB[aq]SZ[19]
(;B[bs];W[br]
(;B[bq];W[as]
(;B[cr]C[RIGHT])
(;B[ds];W[ap]C[Seki]))
(;B[cr];W[bq]))
(;B[cr];W[bq]
(;B[br];W[bs]C[Ko])
(;B[bs];W[br]))
(;B[bq];W[ds]
(;B[bs];W[er]C[Ko])
(;B[er];W[br]
(;B[cr];W[ap])
(;B[bs];W[as]))
(;B[as];W[bs]
(;B[br];W[ap]
(;B[as];W[er]C[Dead by double ko])
(;B[er];W[cr]))
(;B[er];W[br])
(;B[cr];W[ap]))
(;B[cr];W[er]C[Ko])
(;B[br];W[er]C[Ko]))
(;B[br];W[ds]C[Ko])
(;B[ds]
(;W[bq]
(;B[br];W[bs]
(;B[as]C[Ko])
(;B[cr];W[er]))
(;B[bs];W[br])
(;B[cr];W[br])
(;B[as];W[br]))
(;W[br];B[bq];W[ap];B[bs];W[as]C[White can also get seki if ko is not an option.]))
(;B[as];W[bq]
(;B[br];W[cr]MA[bs]MA[ds]C[Black dies by shortage of liberties.])
(;B[cr];W[br])))