use strict;
use warnings;

my %hash = ('a' => 1, 'b' => 2, 'c' => 3);
my $key = (each(%hash))[0];
print $key;
$key = (each(%hash))[0];
print $key;

keys(%hash);

$key = (each(%hash))[0];
print $key;
$key = (each(%hash))[0];
print $key;