In Finnish (or in Tampere, at least) the black shape is called "kahelin kahdeksikko", which roughly translates as "the fool's eight". This is white's strongest play against it.
(;AB[aq]AB[bq]AB[cq]AB[dq]AB[eq]AB[er]AB[es]AW[ap]AW[bp]AW[cp]AW[dp]AW[ep]AW[fp]AW[fq]AW[fr]AW[fs]AW[cr]LB[cn:N]LB[en:H]C[N=normal, H=hardFORCE]AP[goproblems]
(;B[cn];W[en]C[ok, go ahead. Black must avoid ko.]
(;B[bs];W[br]
(;B[cs];W[ar];B[ds]C[RIGHT])
(;B[ar];W[cs]C[1000-year ko.]))
(;B[ar];W[bs];B[ds];W[br];B[cs]C[RIGHT])
(;B[br];W[bs]
(;B[dr];W[cs]C[white will later start a ko with A2.])
(;B[ds];W[ar]C[Two step ko.]))
(;B[cs];W[bs];B[br];W[ds]C[white can later start a ko with A2.])
(;B[ds]
(;W[ar]
(;B[br];W[bs]C[ko.])
(;B[cs];W[bs]C[black dies.])
(;B[bs];W[br];B[cs]C[RIGHT]))
(;W[cs];B[br];W[bs];B[ar]C[RIGHT])))
(;B[en];W[cn]C[Ok, we all know the usual answer. Let's try something else :-)]
(;B[bs]C[NOTTHIS])
(;B[ar]
(;W[cs];B[br];W[bs];B[ds]C[RIGHT])
(;W[br];B[cs]C[RIGHT])
(;W[bs];B[ds]C[RIGHT])
(;W[ds]C[this is a mistake by white.];B[bs];W[br]C[RIGHT]))
(;B[ds]
(;W[bs]
(;B[ar]C[RIGHT])
(;B[br];W[ar]C[two step ko.])
(;B[cs];W[ar]C[oops.]))
(;W[br];B[cs]C[RIGHT])
(;W[cs];B[br];W[bs];B[ar]C[RIGHT])
(;W[ar];B[bs]C[RIGHT]))
(;B[br];W[bs]
(;B[ds];W[ar]C[two step ko.])
(;B[dr];W[cs]))
(;B[cs];W[bs]
(;B[ds];W[ar])
(;B[br];W[ds]))))