(;AB[ar]AB[cs]AB[cr]AB[cq]AB[cp]AB[bp]AB[bo]AW[bs]AW[an]AW[bn]AW[cn]AW[co]AW[ds]AW[dr]AW[dq]AW[dp]TR[an]MA[bs]AP[goproblems]
(;W[br];B[bq]
(;W[ao]C[Black cannot play at ARIGHT]LB[ap:A])
(;W[ap]C[RIGHT]))
(;W[ao]
(;B[br]LB[ap:A]C[Black cannot play at A as White will answer B2CHOICE])
(;B[ap];W[br])))