>Title1
Word1
>Title2
Word2
>Title3
Word3

##</code><code>##

>Apple
>Banana
>Grape

##</code><code>##

Apple Banana Avocado Orange
Grape Apple
Apple Banana Banana

##</code><code>##

Apple occurs: 3
Banana occurs: 3
Grape occurs: 1

##</code><code>##

sub by_count {
   $count{$b} <=> $count{$a};
}

open(INPUT, "<Input.txt");
open(OUTPUT, ">WordFreqs.txt");
$bucket='red|blue|green';

while(<INPUT>){
   @words = split(/\s+/);
   foreach $word (@words){
            if($word=~/($bucket)/io){
      $count{$1}++;}
   }
}
foreach $word (sort by_count keys %count) {
   print OUTPUT "$word occurs $count{$word} times\n";
}

close INPUT;
close OUTPUT;