The Set Cover problem is defined as follows: Input: A finite set U $=\{$e$1,$ e$2,...,$ en$\}$ called the universe, and acollection of subsets S $=\{$S$1,$ S$2,...,$ Sm$\}$ where each Si U$.$ Goal: Find the smallest subcollection C S such that the union ofthe sets in C covers U$,$ i$.$e$.,$ SSC S $=$ U$.($a$)$ Design a Greedy Approximation Algorithm for this problem.$($b$)$ Prove the Approximation Bound of your algorithm