#Actual Script
#!/usr/bin/perl
use strict;
use warnings;
sub add_nums {
	# body...
	# Add numbers entered at STDIN
	print "Enter a number (999) to quit\n";
	(my $n = <>);
	my $sum = 0;
	while ($n != 999) { #causes string to numeric for $n
		$sum += $n;
		($n = <>);
	}
	print "The Sum is $sum\n";
}
add_nums;