Ok I am in AP Chemistry 2 and I have no clue what I am doing... so can someone help me with this problem??

Hexamethylenetetramine was used for the treatment of kidney and bladder infections prior to the development of modern antibiotic drugs. Combustion of 0.2897 g of this compound produced 0.5456 g of CO2 and ).2234 g of H2O. Separate nitrogen assay of a 0.3801 g sample yielded 0.1848 g of ammonia. What is the empirical formula of this compound?