=head1 1

Contents of section 1

=head2 1.1

Contents of section 1.1

=head3 1.1.1

=head4 1.1.1.1

=head1 2

Contents of section 2

=head2 2.1

Contents of section 2.1

=head4 2.1.1

Contents of section 2.1.1

=head3 2.2

Contents of section 2.2

=head1 3

Contents of section 3