You are given an array (a) of length (n), and an integer (k). Let (f(l,r)) be the value of (\operatorname{mex}(a_l,a_{l+1},\ldots,a_r))(^{\text{∗}}). You want to perform the following operation (n-k+1) times: Let the current length of the sequence be (|a|). You need to find an interval (l, r) of length (k) such that (\operatorname{max}_{i=1}^{|a|-k+1} f(i, i+k-1) = f(l, r).) In other words, you need to select a window of size (k) such that among all windows of size (k), the window you selected has the maximum (\operatorname{mex}). If multiple (l,r) exist, you may select any. Then, you must select any integer (i) such that (l \leq i \leq r), and delete (a_i) from (a). That is, your new sequence will be (a_1, a_2, \ldots, a_{i-1}, a_{i+1}, a_{i+2}, \ldots, a_n). For example, in the array (1,2,0,1,3,0) with (k=3), the two possible ((l,r)) pairs are ((1,3)) and ((2,4)) (since they each have (\operatorname{mex} 3), which is the maximum among all windows of size (3)). Therefore, you can remove any one of the indices (1,2,3,4) in your next move. After (n - k + 1) operations, you will have a sequence of length (k-1). Your objective is to maximize the (\operatorname{mex}) of the remaining elements. Please output the maximum (\operatorname{mex}) possible. (^{\text{∗}})The minimum excluded (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 the collection (c). Each test contains multiple test cases. The first line contains the number of test cases (t) ((1 \le t \le 10^4)). The description of the test cases follows. The first line of each test case contains two positive integers (n) and (k) ((2 \le k \le n \le 2 \cdot 10^5)). The second line of each test case contains (n) integers (a_1,a_2,\ldots,a_n) ($$$0 \le