print +(keys %{$var->{'0xAAAAAAAA'}})[1], "\n";
print $var->{'0x55555555'}->{'0xAAAAAAAA'}->[0]->[0], "\n";
print Dumper( $var->{'0x55555555'}->{'0x55555555'} );

gives you

0x55555555
0xAAAAAAAA
$VAR1 = [
          [
            '0xAAAAAAAA',
            '0x9'
          ]
        ];