#!/usr/bin/perl -w

use strict;#:-)
@!=<DATA>;chomp
@!;$_=@!;map{$_
=[split//]}@!;$
0=1;$a=$b=int$_
/2;my$s=sub{for
(0..$!){push@0,
$![$a][$b]|| 0;
${$_[0]}+=$0;}}
;while($!<$_){&
$s(\$b);&$s(\$a
);$!++;$0=-$0;}
eval join'',@0;
    __END__
}}close FILE;}
;_\n";last;}els
1$t && /\S/){pi
 "x; open(FILrf
=tetub wnt{rEi(
 nnxs\&wnt,e,n/
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$"{y' || tf ;Fd
{n)m ;)d-(fiwi\
)\>ELIF<(elihld
ieman::dniF::e\
/)ELTIT|EMAN(+s