my %provisions;
my $person;
while (<>) {
if (/^(\S.*)/) { # a person's name (no leading whitespace)
$person = $1;
} elsif (/^\s+(\S.*)/) { # a provision
die 'No person yet!' unless defined $person;
push @{ $provisions{$person} }, $1;
} else {
die "I don't understand: $_";
}
}

##</code><code>##

my %total_bytes;
while (<>) {
my ($source, $destination, $bytes) = split;
$total_bytes{$source}{$destination} += $bytes;
}
for my $source (sort keys %total_bytes) {
for my $destination (sort keys %{ $total_bytes{$source} }) {
print "$source => $destination:",
" $total_bytes{$source}{$destination} bytes\n";
}
print "\n";
}

##</code><code>##

The Skipper
  blue_shirt 
  hat
  jacket
  preserver
  sunscreen
Professor
  sunscreen
  water_bottle
  slide_rule
Gilligan
  red_shirt
  hat
  lucky_socks
  water_bottle
The Skipper
  sextant

##</code><code>##

professor.hut	skipper.crew.hut	8655
ginger.girl.hut	laser3.copyroom.hut	6404
skipper.crew.hut	fileserver.copyroom.hut	8534
gilligan.crew.hut	skipper.crew.hut	1004
laser3.copyroom.hut	ginger.girl.hut	4366
maryann.girl.hut	professor.hut	8454
skipper.crew.hut	professor.hut	7475
gilligan.crew.hut	maryann.girl.hut	8128
gilligan.crew.hut	maryann.girl.hut	5277
gilligan.crew.hut	fileserver.copyroom.hut	6117
skipper.crew.hut	professor.hut	5101
gilligan.crew.hut	gilligan.crew.hut	9973
ginger.girl.hut	fileserver.copyroom.hut	1448
skipper.crew.hut	gilligan.crew.hut	2146
fileserver.copyroom.hut	gilligan.crew.hut	9568
maryann.girl.hut	laser3.copyroom.hut	8024
fileserver.copyroom.hut	laser3.copyroom.hut	9574