use strict;
use warnings;

##</code><code>##

print "\n Enter the file name :>";
chomp( my $filename1 = <STDIN> );

##</code><code>##

my @lines = ();

##</code><code>##

open my $fh, '<', $filename1 or die "Cannot find the file $filename1: $!";

##</code><code>##

while (<$fh>)
{
    push @lines, $_;

}

##</code><code>##

close $fh;

##</code><code>##

open my $w, '>', 'Result.txt' or die "Cannot open the file Result.txt: $!";

##</code><code>##

foreach my $line (@lines)
{
    my @chr_fields = grep {$_ =~ m/^chr/} split ("\t", $line)

    if (                                   # If...
      @chr_fields == 2                     # ...there are exactly two chr* fields...
      && $chr_fields[0] ne $chr_fields[1]  # ...which are not exactly the same...
    ) {
        print $w $line;
    }
}
close $w;