#!/usr/bin/perl
use strict;
my @array;
my $i;
my $response;
my $sum=0;
# PART A
for($i=0 ; $i<20 ; $i++)
{
$array[$i]=(4*$i)+4;
}
# PART B
do
{
print "Please enter a number between 0 and 19 inclusive ";
$response=;
chomp($response);
if (($response<0) || ($response>19) )
{
print "\nError on input. Number must be between 0 and 19 inclusive\n";
print "Please re-enter\n";
}
} until ( (0<=$response) && ($response <=19) );
print "Number is $array[$response]\n";
# PART C
for($i=0 ; $i<=$response ; $i++)
{
$sum=$sum+$array[$i];
}
print "The sum is $sum\n";