Use the numbers $1$ to $4$ to add up to $4$

Question

It is stated: "A pathway measuring four units in length can be paved in exactly eight different ways using any combination of paving stones measuring one to four units in length."

My attempt: The combinations I could find were: $$1,1,1,1$$ $$2,1,1$$ $$1,2,1$$ $$1,1,2$$ $$3,1$$ $$1,3$$ $$4$$

However, these are only 4 combinations. What combination am I missing?

Answer 1

You seem to have missed $$ 4 = 2 + 2 $$