(;AB[cr]AB[er]AB[eq]AB[dp]AB[do]AB[co]AB[bo]AB[ap]AW[bp]AW[cp]AW[bs]AW[dq]AW[dr]AW[ds]TR[cr]AP[goproblems]
(;W[ar];B[bq];W[cq]C[RIGHT])
(;W[bq];B[ar];W[aq];B[br]LB[cq:A]LB[cs:B]C[White cannot play at A or B]
(;W[cs];B[cq])
(;W[cq];B[es]))
(;W[cq]
(;B[ar]LB[aq:A]LB[br:B]LB[bq:C]C[CHOICE]
(;W[br];B[aq])
(;W[cs];B[br];W[bq];B[aq]))
(;B[aq]C[];W[ar];B[br];W[bq];B[as];W[cs];B[es])
(;B[br];W[bq];B[aq];W[ar];B[as];W[cs];B[es])))