(;AB[aq]AB[bq]AB[cq]AB[dq]AB[dr]AB[fr]AB[fq]AW[ar]AW[br]AW[cr]AW[ds]AW[gs]AW[gr]AW[gp]AW[fp]AW[ep]AW[dp]AW[cp]AW[bo]AW[ao]AW[bp]AB[hq]MA[hq]C[Prevent black from saving any stones.]AB[jq]AB[jr]AW[io]AB[kp]AP[goproblems];W[gq](;B[es]C[CHOICE](;W[cs];B[bs])(;W[bs];B[cs]C[White needs lots of ko threats this way.])(;W[fs];B[eq](;W[er]C[ko])(;W[bs];B[cs]C[ko])(;W[cs];B[bs]C[ko]))(;W[eq](;B[cs]C[CHOICE](;W[bs];B[as]MA[br]MA[er])(;W[er]C[RIGHT])(;W[fs]C[RIGHT])(;W[ap];B[bs](;W[er]C[RIGHT])(;W[fs];B[as])))(;B[er]C[CHOICE](;W[bs];B[cs]C[ko])(;W[cs];B[bs])(;W[ap];B[cs](;W[bs];B[as])(;W[fs]C[RIGHT]))(;W[fs];B[cs](;W[bs];B[as])(;W[ap]C[RIGHT]))))(;W[er];B[eq](;W[fs];B[cs])(;W[bs];B[cs]C[Ko])))(;B[cs]C[CHOICE](;W[bs];B[es]C[ko])(;W[es];B[fs](;W[eq];B[er])(;W[er];B[eq])(;W[bs];B[er](;W[cs];B[as])(;W[ap];B[cs](;W[eq];B[as])(;W[ds]C[RIGHT]))(;W[eq];B[cs](;W[ds]C[RIGHT])(;W[ap];B[as])))(;W[ap];B[er]))(;W[eq];B[er](;W[es];B[fs])(;W[fs];B[es](;W[bs];B[as])(;W[ap]C[RIGHT]))(;W[bs];B[es]C[ko])(;W[ap];B[bs](;W[es];B[fs])(;W[fs];B[as]MA[br]MA[es])(;W[as];B[cs];W[bs];B[cs])))(;W[er];B[eq];W[bs];B[es]C[ko])(;W[fs];B[es](;W[bs];B[as])(;W[ap];B[eq])(;W[eq];B[er](;W[bs];B[as])(;W[ap]C[RIGHT])))))