(;AP[goproblems]AB[ap]AB[bp]AB[cq]AB[br]AB[dp]AB[ep]AB[er]AB[eq]AB[dr]AW[bq]AW[ao]AW[bo]AW[co]AW[cp]AW[do]AW[eo]AW[fp]AW[fq]AW[fr]AW[fs]AW[es]AW[ds]C[Please avoid ko if you can live without ko.](;B[aq];W[bs]LB[fn:tenuki](;B[ar];W[cr];B[cs]C[this ko is heavy for B. there is a way to avoid this ko.])(;B[cr];W[ar];B[as]C[this ko is heavy for B. there is a way to avoid this ko.])(;B[fn];W[ar];B[as];W[cs];B[cr];W[ar]C[this ko is heavy for B. there is a way to avoid this ko.]))(;B[ar];W[bs](;B[cr](;W[aq];B[cs]C[RIGHT])(;W[cs];B[aq]C[RIGHT]))(;B[aq];W[cr];B[cs]C[this ko is heavy for B. there is a way to avoid this ko.]))(;B[cs];W[ar])(;B[bs];W[ar](;B[aq];W[bq])(;B[as];W[aq])))