my @chars = qw[A C G T];
for my $aleph (0..$#chars) {
   $count{$aleph}=0;
   for my $beth (0..$#chars) {
      $count{$aleph.$beth}=0;
      for my $gimal (0..$#chars) {
         $count{$aleph.$beth.$gimal}=0;
      }
   }
}