4. Suppose that we want to find a feasible circulation in the network below with flows on each edge in the specified lower and upper bounds. a [5, 11]- d [3,7] [1,3] [1,6] [1,6] Find a feasible circulation in this network by writing down an equivalent maximum-flow problem, find- ing the maximum flow in that network (using Ford-Fulkerson), and converting it back to an equivalent feasible circulation.