(;GM[1]FF[4]CA[UTF-8]AP[CGoban:3]ST[2] RU[Japanese]SZ[19]KM[6.50] AW[cp][dp][bq][cq][eq][dr][fr][fs]AB[bo][co][do][eo][bp][ep][fq][gq][br][gr][bs][gs]C[Black's move, your task is to kill the group of whites in the corner] (;B[ds] ;W[er] (;B[aq] ;W[cr] (;B[cs]C[Excellent! RIGHT]) (;B[ar] ;W[cs]) (;B[ap] ;W[cs])) (;B[cr] ;W[ar]C[It is only seki]) (;B[ar] ;W[cr] (;B[cs] ;W[aq] ;B[ap]C[It is only seki]) (;B[aq] ;W[cs])) (;B[cs] ;W[ar] (;B[ap] ;W[aq] ;B[cr]C[It is only seki]) (;B[cr]C[It is only seki]))) (;B[aq] ;W[cr] (;B[cs] ;W[ds]) (;B[ds] ;W[cs]) (;B[es] ;W[er] (;B[cs] ;W[ds]) (;B[ds] ;W[cs]))) (;B[es] ;W[er] (;B[cr] ;W[ar] (;B[ap] ;W[aq] (;B[ds] ;W[cs] ;B[ds]C[It is only seki]) (;B[as] ;W[cs])) (;B[ds] ;W[cs] (;B[ds]C[It is only seki]) (;B[ap] ;W[as]) (;B[aq] ;W[as]))) (;B[aq] ;W[cr] (;B[cs] ;W[ds]) (;B[ds] ;W[cs]))) (;B[cr] ;W[ar] (;B[ds] ;W[er]C[It is only seki]) (;B[ap] ;W[aq] (;B[ds] ;W[er]C[It is only seki]) (;B[as] ;W[cs]) (;B[er] ;W[es] ;B[ds] ;W[cs]C[It is only ko])) (;B[er] ;W[es] (;B[ap] ;W[aq] ;B[ds] ;W[cs]C[It is only ko]) (;B[ds] ;W[cs]C[It is only ko]))) (;B[cs] ;W[ds] (;B[aq] ;W[ar]) (;B[cr] ;W[ar])) (;B[ar] ;W[cr] (;B[cs] ;W[ds]) (;B[ds] ;W[cs])))