(;AW[sb]AW[rb]AW[qc]AW[pc]AW[ob]AB[nc]AB[od]AB[pd]AB[qd]AB[rd]AB[rc]AB[nb]AB[mb]AP[goproblems]
(;B[qa];W[pa]
(;B[qb];W[ra])
(;B[ra];W[qb]))
(;B[pa];W[oa]
(;B[qb];W[pb])
(;B[na];W[qa])
(;B[qa];W[ra])
(;B[pb];W[qa];B[oc];W[qb])
(;B[ra];W[qb];B[qa]C[sente seki, white must play p17 to avoid the loss of the whole cornerRIGHT]))
(;B[na];W[oa])
(;B[ra];W[pa]
(;B[qa];W[qb])
(;B[qb];W[qa]))
(;B[oa];W[pa]
(;B[qb];W[qa])
(;B[qa];W[na]
(;B[ra];W[qb])
(;B[qb];W[ra])
(;B[ma];W[qb]
(;B[oc];W[ra])
(;B[oa];W[ra])))
(;B[oc];W[na]
(;B[qb];W[pb])
(;B[qa];W[ra])
(;B[ma];W[pb]))
(;B[pb];W[na])
(;B[na];W[pb]))
(;B[oc];W[pa]
(;B[qb];W[pb])
(;B[na];W[ra]
(;B[pb];W[qb])
(;B[oa];W[pb])
(;B[qb];W[pb]))
(;B[qa];W[qb];B[na];W[ra])
(;B[ra];W[qa])
(;B[pb];W[qb]))
(;B[pb];W[pa]
(;B[qa];W[qb])
(;B[oc];W[qb]))
(;B[qb];W[qa]
(;B[oc];W[pb])
(;B[pa];W[pb])
(;B[sc];W[pb])))