write a go solution for E. MEXimize the Scoretime limit per test2 secondsmemory limit per test256 megabytesinputstandard inputoutputstandard outputSuppose we partition the elements of an array b into any number k of non-empty multisets S_1,S_2,ldots,S_k, where k is an arbitrary positive integer. Define the score of b as the maximum value of operatornameMEX(S_1)^∗+operatornameMEX(S_2)+ldots+operatornameMEX(S_k) over all possible partitions of b for any integer k.Envy is given an array a of size n. Since he knows that calculating the score of a is too easy for you, he instead asks you to calculate the sum of scores of all 2^n-1 non-empty subsequences of a.^† Since this answer may be large, please output it modulo 998,244,353.^∗operatornameMEX of a collection of integers c_1,c_2,ldots,c_k is defined as the smallest non-negative integer x that does not occur in the collection c. For example, operatornameMEX([0,1,2,2])=3 and operatornameMEX([1,2,2])=0^†A sequence x is a subsequence of a sequence y if x can be obtained from y by deleting several (possibly, zero or all) elements.InputThe first line contains an integer t (1<=t<=10^4) — the number of test cases.The first line of each test case contains an integer n (1<=n<=2*10^5) — the length of a.The second line of each test case contains n integers a_1,a_2,ldots,a_n (0<=a_i<n) — the elements of the array a.It is guaranteed that the sum of n over all test cases does not exceed 2*10^5.OutputFor each test case, output the answer, modulo 998,244,353.ExampleInput430 0 140 0 1 150 0 1 2 241 1 1 1Output11
26
53
0
NoteIn the first testcase, we must consider seven subsequences:   [0]: The score is 1.  [0]: The score is 1.  [1]: The score is 0.  [0,0]: The score is 2.  [0,1]: The score is 2.  [0,1]: The score is 2.  [0,0,1]: The score is 3.  The answer for the first testcase is 1+1+2+2+2+3=11.In the last testcase, all subsequences have a score of 0.. Output only the code with no comments, explanation, or additional text.