definiens: means, on a country - by - country and Product - by - Product basis:(a ) For Cempra Products, the period commencing on the First Commercial Sale thereof in a particular country andcontinuing until the later of ( a ) the last to expire Valid Claim of an [COMPANY] Patent covering the manufacture, use or sale ofsuch Cempra Product in such country or ( b ) ten ( 10 ) years following the First Commercial Sale of such Cempra Product in suchcountry ; and(b ) For [COMPANY] Products, the period commencing on the First Commercial Sale thereof in a particular country andcontinuing until the later of ( a ) the last to expire Valid Claim of a Cempra Patent covering the manufacture, use or sale of suchOptimer Product in such country or ( b ) ten ( 10 ) years following the First Commercial Sale of such [COMPANY] Product insuch country