$/=$_;map{binmode$_}\*STDIN,\*STDOUT;while($"=<>){map{$/=substr$",0,4,'';($,, $;)=unpack"aC",$/;$_{(unpack"aCB$;",$/)[2]}=$,}1..ord substr$",0,1,'';($,,$") =unpack"SB*",$";map{$;=1;$;++ until exists$_{substr$",0,$;};$\.=$_{substr$",0 ,$;,""}}1..$,;print""}