(;AB[ra]AB[rb]AB[rc]AB[rd]AB[re]AB[qe]AB[pe]AB[oe]AB[ne]AB[me]AW[qa]AW[pa]AW[qb]AW[qc]AW[qd]AW[pd]AW[od]AW[nd]AW[nc]AW[mc]AW[mb]AW[ma]AB[md]AB[lc]AB[lb]AB[la]C[Black to do their best.]AP[goproblems]
(;B[ob]C[];W[oa]
(;B[nb];W[oc]
(;B[pb]C[Seki is the best black can do.RIGHT])
(;B[na];W[pb])
(;B[pc];W[pb]))
(;B[oc];W[nb])
(;B[pb];W[nb])
(;B[pc];W[nb])
(;B[na];W[nb]))
(;B[oc];W[ob]C[])
(;B[na];W[ob]C[])
(;B[oa];W[ob]C[])
(;B[nb];W[ob]C[])
(;B[pb];W[ob]C[])
(;B[pc];W[ob]C[]))