#!/usr/bin/perl

use 5.14.2;
use strict;
use warnings;
use Data::Dumper;
use diagnostics;

sub metal_stack_order {
	my @unsorted =@_ ;
	
	#make sure to arrange to ascending order
	my @sorted = sort { $a <=>$b} @unsorted;
	my ($Start,$End)=($sorted[0],$sorted[1]);
	
	for (my $i=$Start; $i <= ($End-1) ; $i++){		
		print "M$i --> V$i-->";
	}
	
		
}

say "Enter Lowest metal layer like =>  \"m1\"\n";
my $input1=<>;
say " Enter Highest metal like =>  \"m5 \"\n";
my $input2=<>;


#parsing the metal layer (digits)
my ($num_1)=$input1=~ m/(\d)+/;
my ($num_2)=$input2=~ m/(\d)+/;

#Ony exception, no equal metal layers
if ($num_1 == $num_2){ 
	say "You cannot do a layout  the same layer\n";
	exit;
}


metal_stack_order($num_1,$num_2);