The set cover problem given as follows: provided a set S of subsets S1, ..., Sm of the universal set U={1, ..., n}, determine the smallest subset of subsets T ⊂ S such that ∪ti∈T ti = U. For example, there are the following subsets, S1 = {1, 3, 5}, S2 ={2, 4}, S3 = {1, 4}, and S4 = {2, 5} The set cover would then be S1 and S2. Determine a counterexample for following algorithm on the basis of greedy strategy: Choose the largest subset for cover, and then delete all its elements from the universal set. Repeat by adding the subset consisting of the largest number of uncovered elements until all are covered.