(;FF[4]GM[1]SZ[19]CA[UTF-8]AP[SGFC:1.16] GN[Black to play. Can he save his marked stone?] DT[2009-04-22] PC[http://senseis.xmp.net/?LongestLadderProblem] AB[ab:ac][ap][ar:as][bn:cn][cp][dc:ec][ds][eo:ep][fe:ge][ho:io] [je:ke][kh:ki][km:kn][lk:mk][mm][mo:no][of:og][oj:ok][oq:pq] [qa:ra][qd:qe][sq:sr]AW[ao:bo][aq:bq][br][do:dp]SQ[ap]PL[W] ;SQ[ap])