I am trying to output the file to a new directory ( the files to be modified is in another folder)

but iam getting the error cannot open directory 


My code : 

#!/usr/local/bin/perl -w
# use strict;
# use warnings;
if($#ARGV != 1)
{
	print "usage: perl directory.pl source direcoty  detination directory \n";
	exit;
}

chomp(@ARGV);
#my $dirname = "lab";
#my $output="lab2";

my $dirname = $ARGV[0];
my $output= $ARGV[1];

$dirname =~ s/\/$//g;
$output  =~ s/\/$//g;

mkdir $output if (-d $output ==0);
#`rm $output/*.lab`;
opendir(DIR, $dirname) or die "can't opendir $dirname: $!";

while (defined($file = readdir(DIR))) {
$file2=$file;
$input=$dirname."/".$file;
$out=$output."/".$file2;
print $file."\t".$input."\t".$out."\n";


open(F,"<$input") or die " Cannot open file $input: $!";
open(F1,">$out") or die " Cannot open file $out: $!";

<F>;

#while ($line = readline(F)) {

#$line=~s/^(.*)\n$/$1/s;
#$line=~  s/\r//gi; 
#print F1 $line ;
#}
close (F);
close (F1);
}
closedir(DIR);