#!/usr/bin/perl

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

my @word;

while(<>) {
 chomp;
 my $key = join '', sort split '';
 push @{$word[length]{$key}}, $_;
}


my @ana;
for my $i (reverse 3..$#word) {
  my $got_it;
  for my $key (keys %{$word[$i]}) {
    if (my @chain = find_chain($key)) {
      push @ana, @chain;
      $got_it = 1;
    }
  }
  last if $got_it;
}

for my $chain (@ana) {
  for my $key (@$chain) {
    my $len = length $key;
    print "[ @{$word[$len]{$key}} ]\n";
  }
  print "\n";
}

sub find_chain {
  my $key = shift;
  my $len = length($key)-1;
  return [ $key ] if $len < 3;
  my @rtn;
  my $old_chr = '';
  for my $i (0..$len) {
    my $tmp = $key;
    next if (my $chr = substr($tmp, $i, 1, '')) eq $old_chr;
    $old_chr = $chr;
    next unless exists $word[$len]{$tmp};
    if (my @chain = find_chain($tmp)) {
      unshift @$_, $key for @chain;
      push @rtn, @chain;
    }
  }
  delete $word[$len]{$key} unless @rtn;
  @rtn;
}