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