[Perl] 算複利小程式

#!/perl
use strict;
use warnings;

my $max_month = 20 * 12;
my $curr_month = 0;
my $money = 58390;
my $saving = 0;
my $rate = 0.05 / 12;

while ($curr_month < $max_month) {
    $curr_month++;
    $saving = $saving * (1 + $rate);
    $saving += $money;
}

print "$saving\n";