(;SZ[13]GM[1]FF[4]CA[UTF-8]AP[CGoban:2]ST[2]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]AW[bi]RU[Japanese]TM[]PW[White]PB[Black]C[Black to play and live. (The black stone in Atari is helpful in this problem.)](;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.])))(;B[ac];W[bb](;B[ba];W[ab])(;B[ab];W[ba]))(;B[ca];W[bb])(;B[ad];W[bb](;B[ab];W[ba](;B[ca];W[bc])(;B[bc];W[ca]))(;B[ba];W[ab])(;B[ca];W[ab])))