(;AP[goproblems]AW[ap]AW[bp]AW[cp]AW[dr]AW[ds]AW[bs]AW[ar]AB[cs]AB[cq]AB[co]AB[dp]AB[eq]AB[er]AB[es]AB[bn]AB[dn]C[kill white stones](;B[bq];W[cr](;B[br]LB[dq:A]C[nice, w cannot play at ARIGHT])(;B[dq];W[br])(;B[aq];W[br]))(;B[br];W[bq](;B[as]C[ko!])(;B[cr];W[dq])(;B[dq];W[cr]))(;B[cr];W[bq]LB[br:A]C[cannot play at A])(;B[dq];W[bq]LB[br:A]C[cannot play at A]))