The demand for shoes is given by Q = 10 - P, where Q is the quantity demanded for pairs of shoes. There are two firms: one that sells right shoes and the other that sells left shoes. Let P₁ be the price charged by the right-shoe producer and P₂ be the price charged by the left-shoe producer. Of course, consumers still want to buy a pair of shoes (a right one and a left one). The marginal cost of the right-shoe producer is $1 per shoe, and the marginal cost of the left-shoe producer is $1 per shoe. What is the Bertrand equilibrium price of shoes? How many pairs of shoes are purchased?