#!perl

use strict;
use warnings;
use charnames qw( :full );

open my $input_fh,
    '<:raw:perlio:encoding(UTF-16):crlf', 'Input.txt';
open my $output_fh,
    '>:raw:perlio:encoding(UTF-16LE):crlf', 'Output.txt';

print $output_fh "\N{BYTE ORDER MARK}";

while (my $line = <$input_fh>) {
    chomp $line;
    print $output_fh "$line\n";
}