You are the proud... never mind, just solve this problem. There are (n) intervals (l_1, r_1, l_2, r_2, \ldots l_n, r_n). For each (x) from (0) to (2^m - 1), find the number, modulo (998\,244\,353), of sequences (a_1, a_2, \ldots a_n) such that: (l_i \leq a_i \leq r_i) for all (i) from (1) to (n); (a_1 \oplus a_2 \oplus \ldots \oplus a_n = x), where (\oplus) denotes the bitwise XOR operator . 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 contains two integers (n) and (m) ((1 \leq n \leq 2 \cdot 10^5), (1 \leq m \leq 18)). The (i)-th of the next (n) lines contains two integers (l_i) and (r_i) ((0 \leq l_i \leq r_i < 2^m)). It is guaranteed that the sum of (n) over all test cases does not exceed (2 \cdot 10^5), and the sum of (2^m) over all test cases does not exceed (2^{18}). For each (x) from (0) to (2^m - 1), let: (f_x) be the number of valid sequences, modulo (998\,244\,353); (g_x = f_x \cdot 2^x \mod 998\,244\,353). Here, (f_x) and (g_x) are both integers in the interval (0, 998\,244\,352). Let (h = g_0 \oplus g_1 \oplus \ldots \oplus g_{2^m - 1}). Output a single integer — the value of (h) itself. Do not perform a modulo operation. For the first test case, the values of (f_x) are as follows: (f_0 = 2), because there are (2) valid sequences: (1, 1) and (2, 2); (f_1 = 2), because there are (2) valid sequences: (0, 1) and (2, 3); (f_2 = 2), because there are (2) valid sequences: (0, 2) and (1, 3); (f_3 = 3), because there are (3) valid sequences: (0, 3), (1, 2), and (2, 1). The values of (g_x) are as follows: (g_0 = f_0 \cdot 2^0 = 2 \cdot 2^0 = 2); $$$g_1 = f_1 \cdot 2^1 =