use warnings;
use strict;
use Data::Dumper;

$Data::Dumper::Sortkeys = 1;

my %words;
my $tot = 0;
while (<DATA>) {
    for my $word (split) {
        $words{$word}++;
        $tot++;
    }
}

print Dumper(\%words);
print "The number of words in the file is $tot\n";

__DATA__
a b c
d e 
f g h
a b c