(;AB[rg]AB[qf]AB[pg]AB[pe]AB[oe]AB[od]AB[md]AB[nc]AB[ob]AB[pb]AB[mb]AW[nb]AW[oc]AW[pc]AW[pd]AW[qb]AW[qe]AW[re]AW[rf]C[Hint: The result will be a chosei (eternal life loop.) Ko is not the best...]AP[goproblems]
(;B[rb];W[pa]
(;B[rc]
(;W[qc]C[CHOICE];B[na];W[sg]C[White hanes...Black needs to respond directly in order to avoid White's partial escape. (Note: There is also a newly-discovered way to kill from here!)]
(;B[rh];W[ra]C[Now what?];B[rd];W[qd]C[Now what?]
(;B[sb];W[sd];B[sf];W[sc]C[Here comes the chosei...];B[se];W[sd];B[sf]C[Congratulations! You have achieved eternal life!RIGHT];W[sc]C[Here comes the chosei...];B[se];W[sd];B[sf]C[Congratulations! You have achieved eternal life!RIGHT])
(;B[sc]
(;W[se];B[sa];W[sb])
(;W[sd];B[se];W[sb];B[sa]
(;W[sf];B[qa])
(;W[qa];B[oa];W[sb]))
(;W[sb];B[sa];W[qa];B[sf];W[se];B[oa];W[sb];B[mi];W[ni];B[sa];W[nh];B[sh];W[nj];B[sf];W[sb])))
(;B[sf];W[se]C[Nice! What now?];B[rh];W[sc];B[ra];W[qa]
(;B[rd];W[qd];B[sd];W[sb]C[Unconditional life.])
(;B[oa];W[qd];B[sb];W[rd]C[This also leads to a ko.])))
(;W[oa];B[qd];W[rd];B[sd]C[RIGHT]))
(;B[na];W[rc];B[ra];W[qa]C[Oops...]))
(;B[qa]
(;W[rb]C[CHOICE];B[ra]
(;W[rd]C[CHOICE]
(;B[qc];W[qd];B[sf]
(;W[sc]C[CHOICE];B[se];W[sa])
(;W[se];B[sb];W[rc];B[sc];W[sg];B[rh];W[sd];B[na];W[sa];B[sb]C[]))
(;B[sb]
(;W[rc]C[CHOICE]
(;B[sc];W[sf];B[sd];W[se])
(;B[sf];W[sc];B[se];W[sa]C[ko]))
(;W[sc];B[qc]C[])))
(;W[rc];B[qd];W[qc];B[sf];W[se];B[rd]C[]))
(;W[ra];B[qc];W[pa];B[qd];W[rc];B[sb];W[rd];B[rb];W[sc];B[sf]C[])
(;W[rc];B[rb];W[qc]
(;B[ra]C[])
(;B[sf];W[ra];B[sa];W[sc];B[se];W[rd])))
(;B[rc];W[rb];B[qc];W[qd];B[sb];W[rd]C[White lives unconditionally.])
(;B[qc];W[qd]
(;B[rc];W[rb];B[sd];W[sb];B[sf];W[sc];B[se];W[rd];B[sg])
(;B[rb];W[rc];B[qa]
(;W[sd];B[sf];W[ra];B[sa];W[sb];B[qc]C[ko])
(;W[ra];B[sa];W[qc];B[na];W[sd];B[sf];W[sb]))))