use Data::Dumper;

my %islanders;
while (<DATA>) {
        chomp;
        my ($key, $cnt, $fruit) = split / /;
        $key =~ s/://g;
        $islanders{$key}{$fruit} += $cnt;
}
print Dumper(\%islanders);

__DATA__
Gilligan: 1 coconut
Skipper: 3 coconuts
Gilligan: 1 banana
Ginger: 2 papayas
Professor: 3 coconuts
MaryAnn: 2 papayas

##</code><code>##

$VAR1 = {
          'Ginger' => {
                        'papayas' => '2'
                      },
          'Gilligan' => {
                          'banana' => '1',
                          'coconut' => '1'
                        },
          'Skipper' => {
                         'coconuts' => '3'
                       },
          'MaryAnn' => {
                         'papayas' => '2'
                       },
          'Professor' => {
                           'coconuts' => '3'
                         }
        };