my @list = ('',a..z,A..Z,'_');
 
for my $elem1 (@list){
 for my $elem2 (@list){
  for my $elem3 (@list){
    for my $elem4 (@list){
     for my $elem5 (@list){
      for my $elem6 (@list){

     print $elem1,$elem2,$elem3,$elem4,$elem5,$elem6,"\n"

}}}}}}