(;GM[1]FF[4]CA[UTF-8]AP[CGoban:3]ST[2]RU[Japanese]SZ[13]KM[0.50]PW[White]PB[Black](;AW[fi][gj][ck][dk][ek][gk][cl][gl][cm]AB[fh][gh][bi][di][ei][hi][bj][dj][hj][bk][hk][bl][hl][il](;B[gm];W[fm](;B[em];W[hm];B[el];W[ej];B[gi];W[fj];B[fl];W[dl];B[gm]C[ko])(;B[el]C[almost, but not correct];W[em]C[W gets the vital point];B[dl];W[ej];B[gi];W[fj];B[fl];W[hm]C[seki]))(;B[em]C[someone tried this];W[gm]C[W takes the vital point];B[el];W[ej];B[gi];W[fj];B[fl]C[This is seki (if -and only if - W plays tenuki).(Random info: In Chinese rules B can fill 3 stones inside after dame, so you should count that B has 3 points here.)]))(;AW[dk][ek][fk][gk][bl][cl][hl][hm]AB[bi][gi][cj][dj][ej][hj][ij][ak][bk][al][il][jl][am][bm][gm](;B[dl];W[dm];B[ck];W[el];B[fm]C[unconditional death])(;B[em]C[nope~];W[cm];B[ck];W[fm](;B[fl];W[el];B[dl];W[gl])(;B[dl];W[el];B[dm];W[gl])))(;AW[cj][dj][dk][bl][dl]AB[bi][ci][di][ei][ej][ek][el][gl];B[dm];W[cm];B[bk]C[unconditional death];W[bj];B[aj];W[al];B[ak];W[em];B[ck])(;AW[ej][bk][ck][ek][el][cm]AB[bi][di][ei][fi][gi][bj][cj][fk][fl][gl][bm](;B[em];W[dm](;B[bl]C[official solution];W[cl];B[dk];W[dj];B[ak])(;B[dj]C[This also seems to work. Stupid problem.];W[dk];B[cl];W[fm];B[al]))(;B[bl]C[almost, but...];W[em]C[W again takes the vital point];B[ak];W[al]))(;AW[jj][fk][gk][hk][jk][il][kl][km]AB[ih][kh][ki][fj][gj][hj][kj][ek][kk][dl][el][ll][lm];B[hm];W[gm];B[gl];W[fl];B[fm];W[im];B[ij];W[hl];B[gm];W[em];B[gm];W[fm];B[jl])(;AW[bi][cj][dj][bl][dl]AB[bg][bh][ci][di][ei][ej][ek][el][fl];B[dm];W[cm];B[ck];W[dk];B[bj])(;AW[kd][ke][jf][kf][hg][ig][hh][kh][ii][ji][ki][li][jj][kk]AB[lf][jg][kg][lg][mg][ih][jh][lh][hi][hj][ij][jk][jl][kl];B[lj];W[lk];B[mi];W[kj];B[mj];W[mk];B[ll];W[mh];B[mj];W[le];B[mi])(;AW[ac][bc][be][ce][de][ee][fe][df][ff][dg][eg]AB[bb][cb][cc][dd][ed][fd][ge][cf][gf][cg][fg][gg][bh][dh][eh];B[ae];W[bf];B[bd];W[cd];B[ab])(;AW[fk][gk][hk][ik][el][gl][jl][kl][em]AB[fj][gj][hj][ij][dk][ek][jk][kk][dl][ll][dm][lm];B[il];W[im];B[gm];W[hl];B[km])(;AW[bk][ck][dk][gk][bl][el][gl][bm][gm]AB[aj][bj][cj][dj][ej][fj][gj][hj][ak][hk][al][dl][hl][il][am](;B[em];W[ek];B[fk];W[fl];B[cm])(;B[cm]C[wrong order];W[ek];B[fk];W[em];B[fl];W[dm]))(;AW[ai][bi][di][ei][gi][cj][ck][dl]AB[bh][ch][dh][ci][dj][dk][ek][gk][ik][el];B[ak]C[Bonus problem];W[bl];B[al];W[bj];B[dm];W[cm]C[This makes some kind of ko.]))