#!/usr/bin/perl

%word_hash = ();
@common_words = ('the', 'be', 'to', 'of', 'and', 'in', 'that', 'have',
                 'it', 'for', 'not', 'on', 'with', 'he', 'as', 'is',
                 'was', 'are', 'you', 'do', 'at', 'had', 'i', 'a', 'has',
                 'from', 'an', 'his', 'hers', 'but', 'said', 'him', 'her',
         'they', 'them', 'or', 'am', 'did');

while ($string = <STDIN>)
{
    foreach (@common_words)
    {
        $string =~ s/\b$_\b//gi;
    }
    foreach $word (keys(%word_hash))
    {
        if ($string =~ s/\b$word\b//gi)
        {
            $word_hash{$word}++;
        }
    }
    foreach $word (split /\W/, $string)
    {
        $word_hash{ lc($word) } = 1;
    }
}
foreach $key (sort {$word_hash{$b} <=> $word_hash{$a}} keys%word_hash)
{
    print "$key : $word_hash{$key}\n";
}