B"We start with a permutation a_1, a_2, ldots, a_n and with an empty array b . We apply the following operation k times. On the i -th iteration, we select an index t_i ( 1 <= t_i <= n-i+1 ), remove a_{t_i} from the array, and append one of the numbers a_{t_i-1} or a_{t_i+1} (if t_i-1 or t_i+1 are within the array bounds) to the right end of the array b . Then we move elements a_{t_i+1}, ldots, a_n to the left in order to fill in the empty space. You are given the initial permutation a_1, a_2, ldots, a_n and the resulting array b_1, b_2, ldots, b_k . All elements of an array b are distinct. Calculate the number of possible sequences of indices t_1, t_2, ldots, t_k modulo 998 ,244 ,353 . Each test contains multiple test cases. The first line contains an integer t ( 1 <= t <= 100 ,000 ), denoting the number of test cases, followed by a description of the test cases. The first line of each test case contains two integers n, k ( 1 <= k < n <= 200 ,000 ): sizes of arrays a and b . The second line of each test case contains n integers a_1, a_2, ldots, a_n ( 1 <= a_i <= n ): elements of a . All elements of a are distinct. The third line of each test case contains k integers b_1, b_2, ldots, b_k ( 1 <= b_i <= n ): elements of b . All elements of b are distinct. The sum of all n among all test cases is guaranteed to not exceed 200 ,000 . For each test case print one integer: the number of possible sequences modulo 998 ,244 ,353 . require{cancel} Let's denote as a_1 a_2 ldots cancel{a_i} underline{a_{i+1}} ldots a_n rightarrow a_1 a_2 ldots a_{i-1} a_{i+1} ldots a_{n-1} an operation over an element with index i : removal of element a_i from array a and appending element a_{i+1} to array b . In the first exa"...