#!/usr/bin/perl --
use strict;
use warnings;

my $op = shift @ARGV;
my $result;
$op eq 'add' ?
    ( $result = 0, map { $result += $_ } @ARGV ) :
    ( $result = 1, map { $result *= $_ } @ARGV );
print ( $op eq 'add' ? 'The sum is:' : 'The product is:' );
print " $result\n";