my @words = <DICTIONARY>;

##</code><code>##

  #! /usr/bin/perl -w
  use strict;

  my $input = 'art';

  # Read words from a file instead.
  my @words = ('tar', 'rat', 'fake', 'at', 'unknown');

  my $regex = qr{[$input]+};
  my @matches = grep /^$regex$/, @words;
  print "$_\n" for @matches;