(;GM[1]FF[4]CA[UTF-8]AP[CGoban:2]ST[2] RU[Japanese]SZ[19]KM[0.00]TM[] PW[White]PB[Black]AW[cn][ap][bp][cp][cq][dr][er]AB[gp][aq][bq][dq][eq][fq][ar][cr][gr][as][bs]C[what is white's best in the corner?]PL[W] (;W[cs]CR[cs] ;B[ds]CR[ds] (;W[es]CR[es] ;B[fs]CR[fs] ;W[cs]CR[cs]C[RIGHT ko, and white takes first]) (;W[fs]CR[fs] ;B[fr]CR[fr]) (;W[fr]CR[fr] ;B[fs]CR[fs])) (;W[ds]CR[ds] ;B[fr]CR[fr]C[white is lost]) (;W[es]CR[es] ;B[fs]CR[fs] (;W[cs]CR[cs] ;B[ds]CR[ds]C[this is not the best ko, as black took first]) (;W[ds]CR[ds] ;B[fr]CR[fr])) (;W[fs]CR[fs] ;B[fr]CR[fr] (;W[cs]CR[cs] ;B[ds]CR[ds]) (;W[es]CR[es] ;B[gs]CR[gs])) (;W[fr]CR[fr] ;B[ds]CR[ds]))