Expanding the Western Airlines Hub Location Model

Using the 1,000-mile coverage criterion, expand the Western Airlines hub location model.

The new model should include two new cities: Tucson, AZ and Winnipeg, Canada. Modify the model appropriately, assuming that Tucson and Winnipeg, like all the other cities, are candidates for being hubs and must be covered by at least one hub. What is the new optimal solution in terms of the number of hubs? What cities are covered by each hub?