#use strict;
use warnings;

 $file1 = 'C:/Users/Siddharth/Desktop/our.txt';
 $file2 = 'C:/Users/Siddharth/Desktop/my.txt';

open  $h2, '<', $file2 or die "cannot open file2";

 @a2 = <$h2>;
close $h2;
chomp @a2;
 $match = join '|', @a2;
$match = qr/$match/;

open  $f3,'>',"C:/Users/Siddharth/Desktop/one.txt" or die "$!";
open  $h1, '<', $file1 or die "cannot open file1";
my @a1 = <$h1>;
close $h1;

#print grep {$_ !~ $match} @a1;
 print $f3 grep {$_ !~ $match} @a1;