use strict;

use Data::Dumper;

my %first;
$first{'foo'}{'bar'} = 1;
$first{'foo'}{'baz'} = 2;
$first{'bah'}{'oof'} = 3;

print "First hash:\n";
print Dumper \%first;

my %second = %first;
print "\nSecond hash\n";
print Dumper \%second;

print "\nFirst nested hash address: $first{'foo'}\n";
print "Second nexted hash address: $second{'foo'}\n";