(;AB[qb]AB[qc]AB[rd]AB[re]AB[qg]AB[qh]AB[pd]AW[qd]AW[qe]AW[pf]AW[pg]AW[pc]AW[pb]AW[nd]AW[nf]AW[jc]AW[je]C[Most profitable way for b to use the marked stone]TR[pd]AP[goproblems] (;B[oc];W[ob];B[nb];W[nc] (;B[pa];W[od];B[oa];W[pe];B[mb]C[RIGHT]) (;B[oa];W[od];B[pa];W[pe];B[mb]C[RIGHT])) (;B[pa];W[nb] (;B[na];W[ma];B[oa];W[ob];B[qa];W[mb]C[B can do better]) (;B[oa];W[na] (;B[ob];W[oc];B[qa]C[B can do better]) (;B[pe];W[qf];B[rf]) (;B[qf];W[pe]C[B can do better]))) (;B[qf];W[pe];B[pa];W[ob];B[oa];W[na];B[qa];W[nb]) (;B[ob];W[pa] (;B[od];W[oc]) (;B[oc];W[od])) (;B[oa];W[pa]))