$hash->{a} = 30;
$hash->{b} = 20;
$hash->{c} = 10;
my $string;
foreach (1..30){
my $element = randomKey($hash);
$string .= $element;
}

##</code><code>##

my @array;
foreach $key (keys %{$hash}){
  foreach $value($hash->{$key}){
  push @array,  $key;
 }
}