My idea, his money. What's my stake?

I presented my business idea (product related to health) to a friend. He liked it and will most likely provide 100% of the capital for it.

What I bring to the business: idea, free/discounted ads on celebs' social media accounts through family connections

What he brings to the business: capital, physical place to sell product (gyms his family owns <- not as important as we expect the bulk of the product to sell online)

How do we split the company's stake between us, given that he will provide 100% of the capital?