(;SZ[13]AW[db]AW[dc]AW[dd]AW[ae]AW[ce]AW[bf]AW[cf]AB[cb]AB[cc]AB[bd]AB[cd]AB[be]AB[af]C[Black to play and live. (The black stone in Atari is helpful in this problem.)]AW[bi]GM[1]FF[4]CA[UTF-8]AP[CGoban:2]ST[2]RU[Japanese]KM[0.00]TM[]PW[White]PB[Black]
(;B[bb];W[ac];B[ab]C[ Black lives.RIGHT])
(;B[ab];W[ba];B[ca];W[bb]
(;B[ad];W[bc]C[White kills the black stones.])
(;B[bc];W[ad]
(;B[ac];W[ae];B[ad];W[ag])
(;B[aa];W[ag]C[Black has only one eye left.]))))