Apply a greedy heuristic to the instance of the uncapacitated facility location problem: consider an instance with m $=6$ clients and n $=4$ depots, and costs as shown in the matrix $($cij$)=(6,2,3,4),(1,9,4,11),(15,2,6,3),(9,11,4,8),(7,23,2,9),(4,3,1,5)$ and fij $=(21,16,11,24)($cij $=$ variable costs, fij $=$ fixed costs$)$