(;SZ[13]AB[cc]AB[bd]AB[ce]AB[dc]AB[ec]AB[fc]AB[fb]AB[hb]AW[bc]AW[bb]AW[cb]AW[db]AW[eb]AP[goproblems] (;B[ac];W[ab] (;B[ba];W[ea];B[ca]C[RIGHT]) (;B[ca];W[ba]C[CHOICE]) (;B[ea];W[da];B[ba]C[RIGHT]) (;B[da];W[ea]C[CHOICE])) (;B[ea];W[da] (;B[ba];W[ac];B[aa]C[RIGHT]) (;B[ab];W[ac] (;B[ba];W[aa]C[Just a ko, black can do betterCHOICE]) (;B[aa];W[ba]C[CHOICE])) (;B[ac];W[ab];B[ba]C[RIGHT]) (;B[ca];W[ba]C[CHOICE]) (;B[aa];W[ba]C[CHOICE])) (;B[ba];W[ac] (;B[aa];W[ea];B[ca]C[RIGHT]) (;B[ca];W[aa];B[ab];W[da]C[CHOICE]) (;B[ea];W[aa];B[ab];W[ca]C[CHOICE])))