3. The National Express Parcel Service has established various truck and air routes around the country over which it ships parcels. The holiday season is approaching, which means a dramatic increase in the number of packages that will be sent. The service wants to know the maximum flow of packages it can accommodate (in tons) from station 1 to station 7. The network of routes and the flow capacities (in tons of packages per day) along each route are shown in the following network: 3 1 6 5 0 2 2 4 6 2 4 2 6 2 5 9 3 0 0 6 7 7 0 1 3 4 Determine the maximum tonnage of packages that can be transported per day from station 1 to station 7 and indicate the flow along each branch.