You did not run the code you show us or you would have gotten messages that look like:

lobal symbol "$line" requires explicit package name at noname.pl line 
+5.
Global symbol "$element" requires explicit package name at noname.pl l
+ine 6.
...
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Prefix your code with:

use strict;
use warnings;

my $fname = 'list.txt';

open my $fOut, '>', $fname or die "Can't create $fname: $!\n";
print $fOut <<TESTDATA;
some test data goes here
TESTDATA
close $fOut;

...
[download]

providing some sensible test data where indicated then show us the result of actually running the code.