The startup has not been incorporated yet. It has 2 non technical- and non business-oriented co founders who thought of the original idea. They got government non-diluting grant of $50k, and they used it to develop a technological POC (paid to developrs), and submit a provisional documentation for a patent. They are looking for a CEO and a CTO to take it to the next stage (seed round, and getting to product-market fit). They will continue contributing to the company, but have no distinct role in its next phase. I have an experience of beening the the co founder and the CEO of a funded company.
Unless you are sure the company will be successful, don't do it. Everyone and their mother has a "groundbreaking startup" nowadays. Even 50% of $0 ends up being nothing. Don't get blinded by being "CEO of a startup." Always take a step back and look at it for what it is.
If you ARE sure of the product, it really depends on what you're bringing to the table.