(;AB[br]AB[cs]AB[cq]AB[cp]AB[bo]AB[ao]AW[an]AW[bn]AW[cn]AW[co]AW[do]AW[dp]AW[dq]AW[dr]AW[ds]AB[ar]AB[bp]AB[aq]C[White can't kill Black but has the best result.FORCE]AP[goproblems]
(;W[as]C[FORCE];B[cr])
(;W[bs]C[FORCE];B[cr])
(;W[cr]C[FORCE];B[bs]C[RIGHT]))