(;AB[ra]AB[rb]AB[rc]AB[qb]AB[pc]AB[pd]AB[od]AB[nc]AB[ne]AB[of]AW[qf]AW[qh]AW[nd]AW[md]AW[mc]AW[mb]AW[qa]AW[pa]AW[pb]AW[rd]AW[qd]AW[qc]TR[pb]TR[pa]TR[qa]C[How can white save the three marked stones?]AP[goproblems]
(;W[na];B[ob];W[oa]C[RIGHT])
(;W[nb];B[ob];W[oa];B[na])
(;W[oa];B[na];W[ob];B[nb])
(;W[ob];B[nb];W[na];B[oc])
(;W[oc];B[ob]))