(;GM[1]FF[4]CA[UTF-8]AP[CGoban:2]ST[2] RU[Japanese]SZ[7]KM[0.00] AW[eb][fb][gb][dc][ec][bd][cd][dd][ae][be][cf][df]AB[bb][cb][db][ac][bc][fc][gc][ad][ed][fd][ef][ff]C[Black to win the game.] (;B[da] (;W[ea]C[CHOICE] (;B[ba] ;W[ee] ;B[fe] ;W[de] ;B[dg] ;W[cg] ;B[eg]C[RIGHT Correct. Now you can try ferdi's original problem and learn from the difference.]) (;B[aa] ;W[ee] ;B[fe] ;W[de] ;B[dg] ;W[cg] ;B[eg]C[RIGHT Correct. Now you can try ferdi's original problem and learn from the difference.]) (;B[de] ;W[ba] ;B[aa] ;W[ab]LB[ca:A]C[Black has no ko threat, and he can not play at A.]) (;B[dg] ;W[ba] ;B[aa] ;W[ab]LB[ca:A]C[Black has no ko threat, and he can not play at A.])) (;W[ba]C[CHOICE] ;B[aa] ;W[ab] ;B[ca] ;W[ea] ;B[aa] ;W[ee] ;B[fe] ;W[de] ;B[dg] ;W[cg] ;B[eg]C[RIGHT Correct. Now you can try ferdi's original problem and learn from the difference.])) (;B[aa] ;W[da] ;B[ca] ;W[ea]C[The best black can get from here is jigo.]) (;B[ea] ;W[da]C[Black is dead.]) (;B[de] ;W[da]C[Black is dead.]) (;B[dg] ;W[da]C[Black is dead.]))