You are given two arrays (a) and (b) of length (n). You can perform the following operation an unlimited number of times: Choose an integer (i) from (1) to (n) and swap (a_i) and (b_i). Let (f(c)) be the number of distinct numbers in array (c). Find the maximum value of (f(a) + f(b)). Also, output the arrays (a) and (b) after performing all operations. 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 a single integer (n) ((1 \le n \le 10^5)) — the length of the arrays. The second line of each test case contains (n) integers (a_1, a_2, \ldots, a_n) ((1 \le a_i \le 2n)) — the elements of array (a). The third line of each test case contains (n) integers (b_1, b_2, \ldots, b_n) ((1 \le b_i \le 2n)) — the elements of array (b). It is guaranteed that the sum of (n) over all test cases does not exceed (10^5). For each test case, print a single integer in the first line — the maximum value of (f(a) + f(b)). In the second line, print (n) integers — the elements of array (a) after performing the operations. In the third line, print (n) integers — the elements of array (b) after performing the operations. In the first test case, after applying three operations with (i=2), (i=4), and (i=5), we obtain (a = 1, 3, 4, 5, 2) and (b = 1, 2, 3, 4, 4). After that, (f(a) + f(b) = 5 + 4 = 9). It can be shown that it is not possible to achieve a greater answer. In the second test case, after applying the operations: ()f(2, 3, 4, 2, 1, 5, 6) + f(1, 2, 3, 4, 5, 6, 5) = 6 + 6 = 12()