Suppose G = (V, E) is a directed graph network with a source vertex s and a sink vertex t, and ce= 1 for any e E. Given an integer parameter k, your need to delete k edges from G in order to reduce the maximum s t flow as much as possible. Describe an polynomial-time algorithm to solve this problem. You need to prove the correctness of the algorithm and formally analyze the runtime. (You can consider this task as deleting a subset of E consisting of k edges to make the maximum flow in the new graph as small as possible.)