A new large scale senior community is being developed, and one of the decisions to be made is where to locate the two fire stations that have been allocated to the community. For planning purposes, the community has been divided into five tracts, with no more than one fire station to be located in any given tract. Each station is to respond to all of the fires that occur in the tract in which it is located as well as in the other tracts that are assigned to this station. The following table gives the average response time (in minutes) to a fire in each tract (the columns) if that tract is served by a station in a given tract (the rows). The bottom row gives the forecasted average number of fires that will occur in each of the tracts each year. Formulate this problem situation as an integer programming model.