=Each Russian city has contacted Washington to communicate the number of troops and supplies the city needs at a minimum for reinforcement. After analyzing the requests, General Lankletter has converted the requests from numbers of troops, gallons of gasoline, and so on, to tons of cargo for easier planning. The requirements are listed below.

City Requirements Saint Petersburg 320,000 tons Moscow 440,000 tons Rostov 240,000 tons The president faces a number of restrictions when trying to satisfy the requirements. Early winter weather in northern Russia has brought a deep freeze with much snow. Therefore, General Lankletter is opposed to sending truck convoys in the area. He convinces the president to supply Saint Petersburg only through the air. Moreover, the truck routes into Rostov are quite limited, so that from each port, at most 2,500 trucks can be sent to Rostov. The Ukrainian government is very sensitive about American airplanes flying through its air space. It restricts the U.S. military to at most 200 flights from Berlin to Rostov and to at most 200 flights from London to Rostov.
(The U.S. military does not want to fly around the Ukraine and is thus restricted by the Ukrainian limitations.)
How does the president satisfy each Russian city’s military requirements at minimum cost? Highlight the path to be used between the United States and the Russian Federation on the network.