use strict;
my $i = 0;
sub Recurse
{
   my %hash  = ( 'count' => [$i++] );
   my %hash2 = 10 > $i ? %{Recurse()} : ();
   for( keys %hash2 )
   {
       push @{$hash{$_}}, @{$hash2{$_}};
   }
   return \%hash;
}
my %test = %{Recurse()};
print join ' ', @{$test{count}};