(;AB[bh]AB[bi]AB[ch]AB[di]AB[dj]AB[ck]AB[cl]AB[cm]AB[bm]AB[bn]AW[bo]AW[co]AW[cn]AW[dm]AW[dl]AW[bg]AW[cg]AW[ek]AW[ej]AW[ei]AW[dh]AW[dg]AW[ag]AW[ci]AW[bj]LB[bj:1]C[White plays 1. Black to prevent white from killing him.]AP[goproblems]
(;B[aj]
(;W[ai]
(;B[cj];W[ak]
(;B[al];W[ah]
(;B[bk];W[ci]
(;B[an]C[RIGHT])
(;B[aj]C[RIGHT]))
(;B[an];W[bk];B[bl];W[ci])
(;B[ci];W[aj]
(;B[bk];W[an])
(;B[an];W[bk])))
(;B[bk];W[al];B[aj]C[This is a ko whereas black can live unconditionally.]))
(;B[bk];W[ah]
(;B[al];W[an])
(;B[an];W[al])))
(;W[ak]
(;B[cj];W[ai]
(;B[al];W[ah]
(;B[bk];W[ci]
(;B[an]C[RIGHT])
(;B[aj]C[RIGHT]))
(;B[an];W[bk];B[bl];W[aj]))
(;B[bk];W[al];B[aj]C[This is a ko whereas black can live unconditionally.]))
(;B[bk];W[ai]
(;B[al];W[an]
(;B[cj];W[aj];B[ah]C[RIGHT])
(;B[aj];W[ah]))
(;B[an];W[al];B[cj];W[aj]))))
(;B[bk];W[ai]
(;B[al];W[an]
(;B[aj];W[ah])
(;B[cj];W[aj];B[ah];W[ci]))
(;B[cj];W[aj]
(;B[ak];W[ah]
(;B[al];W[an])
(;B[an];W[al]))
(;B[ah];W[ci]))
(;B[aj];W[ah]
(;B[al];W[an])
(;B[an];W[al])))
(;B[ah];W[ai])
(;B[ai];W[cj];B[dk];W[aj])
(;B[ak];W[ai];B[cj];W[aj];B[bk];W[ah]TR[al]TR[an]
(;B[al];W[an])
(;B[an];W[al]))
(;B[cj]
(;W[aj]
(;B[ah];W[ai];B[ci]C[RIGHT])
(;B[ai];W[ah];B[ci];W[bk]
(;B[bl];W[ak]
(;B[an];W[al])
(;B[al];W[an]))
(;B[ak];W[al];B[bl];W[ak];B[am];W[ak])
(;B[al];W[an]))
(;B[bk];W[ai];B[ak];W[ah]TR[al]TR[an]
(;B[al];W[an])
(;B[an];W[al])))
(;W[ai]C[CHOICE]
(;B[bk];W[aj]
(;B[ah];W[ci])
(;B[ak];W[ah]TR[al]TR[an]
(;B[al];W[an])
(;B[an];W[al])))
(;B[ak];W[aj]
(;B[ah];W[ci])
(;B[bk];W[ah]TR[al]TR[an]
(;B[al];W[an])
(;B[an];W[al])))
(;B[ah];W[ci])
(;B[al];W[aj]TR[an]TR[bk])
(;B[an];W[aj]TR[al]TR[bk])
(;B[aj]
(;W[bk];B[bl];W[ak];B[al]C[RIGHT])
(;W[ak]C[CHOICE]
(;B[bk];W[al];B[aj]C[This is a ko whereas black can live unconditionally.])
(;B[al]
(;W[ah]C[CHOICE]
(;B[an];W[bk];B[bl];W[aj])
(;B[bk];W[ci]
(;B[aj]C[RIGHT])
(;B[an]C[RIGHT])))
(;W[bk];B[bl]C[RIGHT])
(;W[an];B[bk]
(;W[ah];B[aj]C[RIGHT])
(;W[aj];B[ah]C[RIGHT])))
(;B[ah];W[ci])
(;B[an];W[al]))))
(;W[ah];B[aj]C[RIGHT])))