##

A
B
C

##

##

sample output:
wire  power_control;
wire  add_bus;
wire  cpu_control;

##

##

My code

use warnings;
use XML::Simple;
use Data::Dumper;

my $xml=XMLin('sample.xml');
my $roottags=$xml->{tags};
my $topmodule=$roottags->{Module};
my @mod=keys %$topmodule;

foreach my $modules(values %$topmodule)
{
    my $modu_temp=shift(@mod);
    #print "$modu_temp\n";
#my $ins_mod=$modules->{input};
     my @ins=(keys %{$modules->{input}});
     if(exists $ins[0]){}
     else{
     $in_1=$modules->{input};
     @ins=$in_1->{name};
     }
    print @ins, "\n";
   }