##
#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";
chomp(my $n = <>);
my $sum = 0;
while ($n != 999) {
$sum += $n;
chomp($n = <>);
}
print "The Sum is $sum\n";
}
add_nums;
####
#Output
The Sum is 10