This is the easy version of the problem. The difference between the versions is that in this version, (n \le 5000). You can hack only if you solved all versions of this problem. Given a tree (T) with (n) vertices rooted at (1) and a sequence (a) of length (n), count the number of permutations(^{\text{∗}}) (p) of length (n) that satisfy the following condition: For all (1 \le u \le n), there are exactly (a_u) vertices (v) such that (v) is an ancestor of (u) in (T) and (p_v < p_u). Output the answer modulo (998\,244\,353). Input data is selected in such a way that at least one valid permutation exists. (^{\text{∗}})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). Each test contains multiple test cases. The first line contains the number of test cases (t) ((1 \le t \le 2500)). The description of the test cases follows. The first line of each test case contains an integer (n) ((2 \le n \le 5000)) — the number of vertices. The second line of each test case contains (n-1) integers (fa_2,fa_3,\ldots,fa_n) ((1 \le fa_i < i))— (fa_i) is the parent of (i) on (T). The third line of each test case contains (n) integers (a_1,a_2,\ldots,a_n) ((0 \le a_i < n)). It is guaranteed that the sum of (n) over all test cases does not exceed (5000). Input data is selected in such a way that at least one valid permutation exists. For each test case, output one integer — the number of permutations modulo (998\,244\,353). Visualizer link In the first test case, the only permutation which satisfies the condition is (1,2,3,4,5). In the second test case, p