use strict;
use warnings;


my @lines;
my @lines2;

my $line;
my $line2;



open (OF, "> diff3.txt");
open (F2, "20100331.txt");
open (F, "20100316.txt");

	while (<F>) {
	
		@lines=(<F>);
			
			}
close (F);

	while (<F2>) {
	
		@lines2 = (<F2>);
		
			}
close (F2);

	foreach $line (@lines) { 
	
		foreach $line2 (@lines2) { print OF $line2 if ($line2 ne $line)}
		
		$line="";
		$line2="";
		 } 
		
close (OF);