my ($a,$b,$c);
for($a = 3; $a < 31; $a++){
    ($a % 2 == 0) ? ($c = ($b = ($a ** 2 / 4) - 1) + 2) : ($c = ($b = ($a ** 2/2) - .5) + 1);
    if((my $num = ($a + $b + $c)) % 5 == 0){
        if((1000/$num) =~ /^\d+$/){ print ((${^MATCH} ** 3 * ($a*$b*$c)) . "\n"); exit;}
    }
}