package liste;
sub new
{
  my $self={list=>[@_]};
  bless($self);
  return $self;
}

sub next
{
  my $self=shift(@_);
  my $l=$self->{list};
  push(@$l,shift(@$l));
  return $$l[0];
}

sub before
{
  my $self=shift(@_);
  my $l=$self->{list};
  unshift(@$l,pop(@$l));
  return $$l[0];
}

sub now
{ 
  my $self=shift(@_);
  return $$self->{list}[0];
}
package main;

my $list=liste::new(was, wie,wo,wann,wozu,wieso);

for(0..6)
{
  print $list->next();
  print "\n";
}