foreach my $e (@calendar) {  $union{$e} = 1  }
  
  foreach $e (@Calendararray)  {
      if ($union{$e})  {  $intersect{$e} = 1  }
      $union{$e} = 1;
  }
  
  @intersect = keys %intersect;
  @union = keys %union;

##</code><code>##

@calendar= qw~ 1 ~; 
@Calendararray=qw~ 2 2 ~;