#!/usr/bin/perl

use warnings;
use strict;

use vars qw($a $b $c $d $x);

$a = 500;

$x = 0;
while ($x < 30) {
    $b = $a;
    $a = $a / 2;
    $c = ($b - $a) / 2;
    $d = ($b + $a) / 2;
    print "$c\n$d\n";
    $a += 2;
    $x ++;
}