Yelkao sunglasses is developing sunglasses based on a modular design concept (frame style, lens type, and storage case) that consumers could order direct from their website and have it shipped within 24 hours. They want launch the product with a campaign that emphasizes "over 2000 combinations" are possible for consumers to choose from. So far, Yelkao has developed 18 different frame styles, which are all compatible with 14 different lens types. What is the minimum number of storage case options (assuming they are compatible with all possible frame style and lens type combinations) they must develop to meet their marketing campaign goal?