WORD: while (my $word = pop @words) {
   # lower-case it
   $word = lc $word;

   # search for the entry
   for my $index (0 .. $#words) {
      if ($counta[$index][0] eq $word) {
         # when found, update the count and 
         # go to the next word
         $counta[$index][1]++;
         next WORD;
      }
   }

   # If there's no entry, add a new entry
   push @counta, [ $word, 1 ];
}