The supply chain for Pappy Van Winkle bourbon is characterized by a monopolist upstream producer and a competitive downstream retail sector. Final consumers' demand for Pappy Van Winkle bourbon is given as:

P=140-2Q,

where Q is the number of bottles that are purchased each day. The marginal cost of production (i.e., performing the manufacturing function) can be written as: MC_M=30+2Q, and the marginal cost of performing the retail function is MC_A=20.

Suppose that the two firms are not vertically integrated. Construct the final consumers' demand curve.

please show step by step process without calculus