DOG: for my $dog (@_) {
    my $remaining = $letters;
    $remaining =~ s/$_//i or next DOG for split //, $dog;
    push @remain, $remaining;
    push @dogs, $dog;
  }
  while( my $dog = shift @dogs ) {
    dogtree( "$tree $dog", shift @remain, @dogs );
  }

##</code><code>##

"A(11),B(3),C(2),D(8),E(6),F(1),H(8),I(10),J(1),K(1),L(6),M(1),N(10),O(9),P(2),R(7),S(6),T(9),U(7),V(1),W(1),X(1),Z(2)";