(;SZ[19]AW[da]AW[cb]AW[eb]AW[cc]AW[ec]AW[ed]AW[ce]AW[de]AW[bf]AW[cg]AB[db]AB[bc]AB[dc]AB[bd]AB[cd]AB[dd]AB[be]C[Black to live - easy one]GM[1]FF[4]CA[UTF-8]AP[CGoban:2]ST[2]RU[Japanese]KM[0.50]PW[white]PB[black]
(;B[ba];W[ca]
(;B[bb];W[ea]
(;B[ae]C[RIGHT])
(;B[ab]C[RIGHT]))
(;B[ab]C[bA18 works but is gote and fills in a point of your territory. bB18 atari is a better move and more likely to be sente.RIGHT]))
(;B[bb];W[ba]C[Mistake often made in our games];B[ca];W[cb])
(;B[ca];W[ba]))