3. Suppose there is a sequence of 2n real numbers such that the first n1/2 elements and last n elements are sorted whereas the remaining elements are unsorted and each of these unsorted elements are integers between n and +n. Devise an algorithm of complexity O(n) to sort the sequence of 2n real numbers. Prove that the complexity of the algorithm is O(n). Note: n1/2 can be assumed to be an integer. [10 Marks]