#!/usr/bin/perl 

package Mysimple_mod;
use strict;
use warnings;

require Exporter;
our @ISA=qw(Exporter);
our @EXPORT_OK = qw( external );

sub external {
	my $val = shift;
	my $return_val = internal($val); 
	return $return_val;
	}

sub internal {
	my $val = shift;
	my $calc = $val * 3;
	return $calc;
	}

1;