(;AB[bq]AB[cq]AB[dq]AB[eq]AB[dp]AB[gq]AB[fp]AB[fo]AB[go]AB[cn]AB[bl]AB[bk]AW[bo]AW[co]AW[do]AW[eo]AW[ep]AW[cp]AW[fn]AW[gp]AW[fq]AW[cl]AW[dk]AB[ci]C[How to deal with the marked black?
]AB[di]AB[hn]TR[cn]AP[goproblems]
(;W[cm];B[bn];W[bm];B[am]
(;W[dn];B[an]
(;W[al];B[ak]
(;W[ao];B[al];W[bj]C[RIGHT])
(;W[bj]C[RIGHT]))
(;W[ao];B[al];W[bj]C[RIGHT])
(;W[bj]C[RIGHT]))
(;W[an];B[ao]
(;W[dn];B[ap])
(;W[ap];B[an]))
(;W[al]
(;B[an]C[CHOICE]
(;W[ao];B[ak]
(;W[dn];B[al];W[bj]C[RIGHT])
(;W[bj]C[RIGHT]))
(;W[dn];B[ak]
(;W[ao];B[al];W[bj]C[RIGHT])
(;W[bj]C[RIGHT]))
(;W[bj]C[RIGHT]))
(;B[ak]C[CHOICE]
(;W[dn];B[an]
(;W[ao];B[al];W[bj]C[RIGHT])
(;W[bj]C[RIGHT]))
(;W[ao];B[an]
(;W[dn];B[al];W[bj]C[RIGHT])
(;W[bj]C[RIGHT]))
(;W[bj]C[RIGHT])))
(;W[ao];B[an]
(;W[dn];B[al];W[bj]C[RIGHT])
(;W[al];B[ak];W[dn];B[al];W[bj]C[RIGHT])
(;W[bj]C[RIGHT])))
(;W[bm];B[fl]C[white group is under attack])
(;W[bn];B[fl]C[white group is under attack])
(;W[dn];B[bm]C[white group is under attack]))