The cost to send a package between two cities is $9.00 for any weight less than 1 pound. The cost increases by $7.00 when the weight reaches 1 pound and again each time the weight reaches a whole number of pounds after that. Express the shipping cost C (in dollars) as a function of the weight w (in pounds). Express your answer in terms of the greatest integer function, ⌊w⌋. Do not use dollar signs ($) in your answer.

C(w) = + ⌊w⌋