christmas stamps

dc3

When I purchased the Christmas stamps, I was unable to get a sheet. Only the 2-sided booklet. Can anyone tell me what constitutes the plate block for these stamps? There are 4 stamps on the front with a number which normally would be the block but there are also 4 attached directly on the back. Can I use these 4 on the back or are they needed to make the plate block??
THANX
dc3