Suppose we partition the elements of an array b into any number k of non-empty subarrays S1,S2,…,Sk , where k is an arbitrary positive integer. Define the score of b as the maximum value of MEX(S1)+MEX(S2)+…+MEX(Sk) over all possible partitions of b for any integer k n <= 2e5 (continous subarrays) how can i calculate score .