@sampleValues = (0, 1, 2, 3, 4, 5, 6, 10, 20, 30, 35);

foreach ( @sampleValues ) {
   print "fibonacci( $_ ) = ", fibonacci( $_ ), "\n";
}

sub fibonacci
{
   my $number = shift;  # get the first argument

   if ( $number == 0 or $number == 1 ) { # base case
      return $number;
   } 

   else {                                # recursive step
      return fibonacci( $number - 1 ) + fibonacci( $number - 2 );
   }
}