#!/usr/bin/perl
use strict;
use warnings;
my $filein = ....
my $fileout = ...;
open(INFILE, $filein) || die "Can’t open input ’$filename’: $!\n";
open(OUTFILE, "> fileout") || die "Can’t open output ’$filename’: $!\n";
while (my $input_line = <INFILE>) {
  chomp($input_line);
  my $output_line = '';
#   FILL IN CODE HERE 
  print OUTFILE "$output_line\n";
}