$"=$/=$_;map{binmode$_}\*STDIN,\*STDOUT;sub r{my($n,$s,$t,$c)=@_;$c=$$n[0];
return$,++,$_{$c}=$s,push@0,pack"aCB16",$c,$t,$s if!ref($c);map r($$c[$_],
$s.$_,$t+1),0,1}sub h{$/=\1;$0{$_}++,$;.=$_ while<>;@_=map[$_,$0{$_}],keys
%0;while(@_>1){@_=sort{$$b[1]<=>$$a[1]}@_;$l=pop;$r=pop;push@_,[[$l,$r],
$$l[1]+$$r[1]]}r pop;$;=~s/./$_{$&}/gs;chr($,)."@0".pack("SB*",$.,$;)}if(
pop@ARGV){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
""}}else{print h}