B'A palindrome is a string that reads the same backwards as forwards. For example, the string abcba is palindrome, while the string abca is not. Let p(t) be the number of unique palindromic substrings of string t , i. e. the number of substrings t[l ... r] that are palindromes themselves. Even if some substring occurs in t several times, it 's counted exactly once. (The whole string t is also counted as a substring of t ). For example, string t = abcbbcabcb has p(t) = 6 unique palindromic substrings: a, b, c, bb, bcb and cbbc. Now, let 's define p(s, m) = p(t) where t = s[1 ... m] . In other words, p(s, m) is the number of palindromic substrings in the prefix of s of length m . For example, p( abcbbcabcb , 5) = p( abcbb ) = 5 . You are given an integer n and k "conditions" ( k <= 20 ). Let 's say that string s , consisting of n lowercase Latin letters, is good if all k conditions are satisfied at the same time. A condition is a pair (x_i, c_i) and have the following meaning: Look in Notes if you need further clarifications. Each test contains multiple test cases. The first line contains the number of test cases t ( 1 <= t <= 10^4 ). The description of the test cases follows. The first line of each test case contains two integers n and k ( 3 <= n <= 2 cdot 10^5 ; 1 <= k <= 20 ) -- length of good string s and number of conditions. The second line of each test case contains k integers x_1, x_2, ... , x_k ( 3 <= x_1 < x_2 < ... < x_k = n ) where x_i is the length of the prefix in the i -th condition. The third line of each test case contains k integers c_1, c_2, ... , c_k ( 3 <= c_1 <= c_2 <= ... <= c_k <= min{ <= ft(10^9, frac{(n + 1) n}{2} right)} ) where c_i is the number of palindromic substrings in the $$'...