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