Try to loose some var names, and your loops are too obvious. This is another 'less-obvious' aproach:

#!/usr/bin/perl
@z=('')x11;s ss5397969880949610291891037060746998929510499113s;
push @s, $1 while (m/(102|103|104|113|..)/g);@z=('')x eval($#z*
2+1);$f = join '', map { chr(eval("$#z+1-$_+$s[$_]"))} (0..@z);
$f=~ s s(.{4})(.{7})(.{4})(.{6})s$1 $2 $3 $4sg;print $f ; eval;
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I know, it's not that good, but I've never been very good at obfuz.