34. Consider the maximum flow problem in the following graph.

Let $s$ be the source node and $t$ be the sink node. A flow in the network is indicated by the numbers on the edges. The edge capacities are exactly the same as the flows as shown in the graph. (For example, the number 4 on edge (s, e) represents that the flow is 4, and that the capacity is also 4, and that the number x on edge (s, a) represents that the flow is x, and that the capacity is also x.)