B'You are given a permutation a_1,a_2, ldots,a_n of integers from 0 to n - 1 . Your task is to find how many permutations b_1,b_2, ldots,b_n are similar to permutation a . Two permutations a and b of size n are considered similar if for all intervals [l,r] ( 1 <= l <= r <= n ), the following condition is satisfied: operatorname{MEX}([a_l,a_{l+1}, ldots,a_r])= operatorname{MEX}([b_l,b_{l+1}, ldots,b_r]), where the operatorname{MEX} of a collection of integers c_1,c_2, ldots,c_k is defined as the smallest non-negative integer x which does not occur in collection c . For example, operatorname{MEX}([1,2,3,4,5])=0 , and operatorname{MEX}([0,1,2,4,5])=3 . Since the total number of such permutations can be very large, you will have to print its remainder modulo 10^9+7 . In this problem, a permutation of size n is an array consisting of n distinct integers from 0 to n-1 in arbitrary order. For example, [1,0,2,4,3] is a permutation, while [0,1,1] is not, since 1 appears twice in the array. [0,1,3] is also not a permutation, since n=3 and there is a 3 in the array. Each test contains multiple test cases. The first line of input contains one integer t ( 1 <= t <= 10^4 ) -- the number of test cases. The following lines contain the descriptions of the test cases. The first line of each test case contains a single integer n ( 1 <= n <= 10^5 ) -- the size of permutation a . The second line of each test case contains n distinct integers a_1,a_2, ldots,a_n ( 0 <= a_i lt n ) -- the elements of permutation a . It is guaranteed that the sum of n across all test cases does not exceed 10^5 . For each test case, print a single integer, the number of permutations similar to permutation a , taken modulo 10^9+7 . For the first test cas'...