B' n people gathered to hold a jury meeting of the upcoming competition, the i -th member of the jury came up with a_i tasks, which they want to share with each other. First, the jury decides on the order which they will follow while describing the tasks. Let that be a permutation p of numbers from 1 to n (an array of size n where each integer from 1 to n occurs exactly once). Then the discussion goes as follows: A permutation p is nice if none of the jury members tell two or more of their own tasks in a row. Count the number of nice permutations. The answer may be really large, so print it modulo 998 ,244 ,353 . The first line contains a single integer t ( 1 <= t <= 10^4 ) -- the number of test cases. The first line of the test case contains a single integer n ( 2 <= n <= 2 cdot 10^5 ) -- number of jury members. The second line contains n integers a_1, a_2, ... , a_n ( 1 <= a_i <= 10^9 ) -- the number of problems that the i -th member of the jury came up with. The sum of n over all test cases does not exceed 2 cdot 10^5 . For each test case, print one integer -- the number of nice permutations, taken modulo 998 ,244 ,353 . Explanation of the first test case from the example: There are two possible permutations, p = [1, 2] and p = [2, 1] . For p = [1, 2] , the process is the following: So, the second jury member has told two tasks in a row (in succession), so the permutation is not nice. For p = [2, 1] , the process is the following: So, this permutation is nice. '...