(;AW[as]AW[ar]AW[aq]AW[cq]AW[cp]AW[co]AW[cn]AW[cm]AW[cl]AW[al]AW[bk]AW[bj]AW[bi]AW[es]AW[er]AW[eq]AW[fp]AB[ds]AB[dr]AB[cr]AB[cs]AB[bq]AB[bp]AB[bo]AB[bn]AB[bm]AB[bl]C[White to cause some trouble in Black's stomach.Hint: Looks like the snapback needs some preparation?]AP[goproblems] (;W[an] (;B[am]C[CHOICE];W[br];B[ak];W[dq];B[ap];W[bs];B[cr];W[cs];B[ds];W[br];B[bs];W[ar];B[aq];W[dr];B[as];W[br];B[ar];W[cs]C[Correct! Three stones are enough to create one troublesome ko for Black :)RIGHT]) (;B[ao];W[br];B[am];W[dq]C[RIGHT])) (;W[br];B[ap] (;W[dq];B[bs];W[ar];B[br]) (;W[am];B[bs];W[ar];B[an];W[br];B[ak];W[al];B[aq];W[dq];B[as]C[Black lives.]) (;W[an] (;B[bs];W[ar];B[am];W[br];B[ak] (;W[dq];B[aq];W[as];B[cr];W[cs];B[bs];W[dr];B[br]) (;W[aj];B[aq];W[al];B[as]) (;W[as];B[aq];W[br];B[ar]) (;W[aq];B[as])) (;B[am];W[dq];B[bs];W[ar];B[br]))) (;W[am];B[an];W[ap];B[br];W[dq];B[ak];W[al];B[bs]C[Black lives in the corner.]))