(;AB[bs]AB[aq]AB[ao]AB[an]AB[bn]AB[cn]AB[dn]AB[en]AB[eo]AB[ep]AB[eq]AB[er]AB[es]AW[ds]AW[dr]AW[dq]AW[dp]AW[do]AW[co]AW[bo]AW[br]AW[ar]AP[goproblems]
(;B[bp]
(;W[bq]C[CHOICE];B[ap];W[cp];B[cr]C[RIGHT])
(;W[cs];B[cq];W[bq];B[ap]C[RIGHT]))
(;B[bq];W[cq];B[bp];W[cs])
(;B[ap]
(;W[cq]LB[bq:A]LB[bp:B]C[CHOICE]
(;B[bq];W[bp])
(;B[bp];W[cs];B[bq];W[as]))
(;W[bq]C[A mistake by White that reverts to solution];B[bp];W[cp];B[cr]C[RIGHT])
(;W[bp])))
