(;AB[rb]AW[qb]AW[pb]AW[rc]AW[rd]AW[qd]AB[qc]AB[pc]AB[pd]AB[od]AB[ob]AB[nc]AW[oe]AW[pe]AW[pf]AW[qf]AW[rf]AB[re]AB[qe]AB[ne]AB[nf]TR[rb]C[capture the marked stone]AP[goproblems]
(;W[ra];B[sb]
(;W[qa];B[oa]
(;W[se];B[pa];W[sc];B[sa]
(;W[qb]C[RIGHT])
(;W[qa];B[qb]))
(;W[sc];B[sd])
(;W[sa];B[pa])
(;W[pa];B[sa])
(;W[sd];B[pa]
(;W[sc];B[se])
(;W[se];B[sa];W[qb];B[qa])))
(;W[sc];B[sd])
(;W[sd];B[pa])
(;W[se];B[pa])
(;W[pa];B[oa])
(;W[oa];B[qa];W[pa];B[na])
(;W[sa];B[qa]))
(;W[sb];B[ra]
(;W[qa];B[pa])
(;W[sc];B[pa])
(;W[sd];B[pa]))
(;W[qa];B[ra])
(;W[sc];B[sb]
(;W[se];B[qa])
(;W[ra];B[sd])
(;W[sd];B[se]))
(;W[sd];B[qa])
(;W[se];B[qa])
(;W[pa];B[oa]))