(;AB[pd]AB[qg]AB[qp]AB[po]AB[fq]AB[kq]AB[de]AB[gd]AW[nc]AW[pm]AW[pj]AW[dc]AW[ee]AW[dh]AW[dq]AW[co]AB[ef]AW[fe]AB[dd]AW[ec]AB[cc]AW[fc]AB[ff]AW[ge]AB[cb]AW[df]AB[dg]AW[cf]AB[cg]AW[bd]AB[ce]AW[bf]AW[be]AB[cd]AB[bg]AB[bh]AB[bi]AW[eg]AW[ci]C[You are Rui Naiwei playing Lee Chang-ho. Can white capture the marked stones? Play at R17 if you think it isn't possible.]MA[qc]TR[ef]TR[ff]AP[goproblems] (;W[qc]C[Good Reading!RIGHT]) (;W[fg];B[gf];W[hf];B[gg];W[gh];B[hg];W[ig];B[hh];W[hi];B[ih];W[jh];B[ii];W[ij];B[ji];W[ki];B[jj];W[jk];B[kj];W[lj];B[kk];W[kl];B[lk];W[mk];B[ll];W[lm];B[ml];W[nl];B[mm];W[mn];B[nm] (;W[nn];B[om] (;W[on];B[ol];W[ok];B[pl];W[ql];B[nk];W[pk];B[mj]C[Oh no white is collapsing]) (;W[ol];B[on];W[oo];B[pn]C[Uh oh!])) (;W[om];B[nn];W[no];B[on] (;W[pn];B[oo]C[Black escapes, white is doomed!]) (;W[oo];B[pn]C[Black is out white is in trouble!]))) (;W[gg];B[fg];W[fh];B[eh];W[gf];B[eg]) (;W[gf];B[fg];W[fh];B[gg];W[hg];B[gh];W[gi];B[hh];W[ih];B[eh];W[hi];B[fi]C[Uh oh]))