B'You are given an integer n and an array a of length n-1 whose elements are either 0 or 1 . Let us define the value of a permutation ^ dagger p of length m-1 ( m <= q n ) by the following process. Let G be a graph of m vertices labeled from 1 to m that does not contain any edges. For each i from 1 to m-1 , perform the following operations: Then, the value of p is the number of incoming edges of vertex 1 of G . For each k from 1 to n-1 , find the sum of values of all k! permutations of length k . Since this value can be big, you are only required to compute this value under modulo 998 ,244 ,353 . ^ dagger A permutation of length n is an array consisting of n distinct integers from 1 to n in arbitrary order. For example, [2,3,1,5,4] is a permutation, but [1,2,2] is not a permutation ( 2 appears twice in the array), and [1,3,4] is also not a permutation ( n=3 but there is 4 in the array). ^ ddagger The weakly connected components of a directed graph is the same as the components of the undirected version of the graph. Formally, for directed graph G , define a graph H where for all edges a to b in G , you add an undirected edge a <= ftrightarrow b in H . Then the weakly connected components of G are the components of H . ^{ dagger dagger} Note that a vertex that has no edges is considered to have only incoming edges. The first line contains a single integer t ( 1 <= t <= 10^4 ) -- the number of test cases. The description of test cases follows. The first line of each test case contains a single integer n ( 2 <= n <= 5 cdot 10^5 ). The second line of each test case contains n-1 integers a_1, a_2, ldots, a_{n-1} ( a_i is 0 or 1 ). It is guaranteed that t'...