#!/usr/bin/perl
use strict;
use warnings;
use 5.010;

running_sum( 5, 6 );
running_sum( 1..6 );
running_sum( 4 );

sub running_sum {
    state $sum = 0;
    state @numbers;

    foreach my $number ( @_ ) {
        push @numbers, $number;
        $sum += $number;
    }

say "The sum of (@numbers) is $sum";
}