#!/usr/bin/perl

use strict;
use warnings;

my  $n1 = 10;
our $n2 = 20;

sub foo {
    $n1++;  # ???
    $n2++;
}

print "$n1\n";
print "$n2\n";
foo;
print "$n1\n";
print "$n2\n";

##</code><code>##

10
20
11
21

##</code><code>##

my $bar = 2;

{
    print "Hi \$bar ($bar), good to see you.\n";
}