(;GM[1]FF[4]CA[UTF-8]AP[CGoban:2]ST[2] RU[Japanese]SZ[19]KM[0.00] PW[Weiß]PB[Schwarz]AW[da][db][dc][dd][fd][ae][ce][cf][bg][bh]AB[ca][cb][cc][bd][cd][de][df][cg][dg]C[White to play - can he kill the black corner?]PL[W] (;W[bb]CR[bb] (;B[ab]CR[ab] ;W[ba]CR[ba]C[Black is dead RIGHT CHOICE]) (;B[ad]CR[ad] (;W[be]CR[be] ;B[ab]CR[ab] ;W[ba]CR[ba]C[Black is dead RIGHT CHOICE]) (;W[bf]CR[bf] ;B[ab]CR[ab] (;W[bc]CR[bc] ;B[ba]CR[ba]C[Black lives]) (;W[ba]CR[ba] ;B[bc]CR[bc]C[Black lives])))) (;W[ad]CR[ad] ;B[ac]CR[ac] (;W[ab]CR[ab] ;B[bf]CR[bf]C[Black is alive]) (;W[be]CR[be] ;B[bb]CR[bb]C[Black lives])) (;W[be]CR[be] ;B[ab]CR[ab]C[Black lives. For the continuation, please check the next two problems!]) (;W[ab]CR[ab] ;B[ad]CR[ad] ;W[be]CR[be] ;B[bb]CR[bb] ;W[ac]CR[ac] ;B[aa]CR[aa]C[This is only a ko]))