#!/usr/bin/perl -l

use strict;
use warnings;

my (@gilligan) = qw(
    red_shirt
    hat
    lucky_socks
    water_bottle
);

check_require_items( 'gilligan', @gilligan );

sub check_require_items {
    use strict;
    use warnings;
    
    my $who = shift();
    my (%whos_items) = map( { $_, 1; } @_ );

    my (@required) = qw(
        preserver
        sunscreen
        water_bottle
        jacket
    );
    
    foreach my $item (@required) {
        unless ( $whos_items{$item} ) {
            print "$who is missing $item.";
        }
    }
}