B. Woeful Permutationtime limit per test1 secondmemory limit per test256 megabytesinputstandard inputoutputstandard outputI wonder, does the falling rain Forever yearn for it's disdain?Effluvium of the MindYou are given a positive integer n.Find any permutation p of length n such that the sum \operatorname{lcm}(1,p_1) + \operatorname{lcm}(2, p_2) + \ldots + \operatorname{lcm}(n, p_n) is as large as possible. Here \operatorname{lcm}(x, y) denotes the least common multiple (LCM) of integers x and y.A permutation is an array consisting of n distinct integers from 1 to n in arbitrary order. For example, [2,3,1,5,4] is a permutation, but [1,2,2] is not a permutation (2 appears twice in the array) and [1,3,4] is also not a permutation (n=3 but there is 4 in the array).InputEach test contains multiple test cases. The first line contains the number of test cases t (1 \le t \le 1\,000). Description of the test cases follows.The only line for each test case contains a single integer n (1 \le n \le 10^5).It is guaranteed that the sum of n over all test cases does not exceed 10^5.OutputFor each test case print n integers p_1, p_2, \ldots, p_n — the permutation with the maximum possible value of \operatorname{lcm}(1,p_1) + \operatorname{lcm}(2, p_2) + \ldots + \operatorname{lcm}(n, p_n).If there are multiple answers, print any of them.ExampleInput
212Output
1 
2 1 
NoteFor n = 1, there is only one permutation, so the answer is [1].For n = 2, there are two permutations:   [1, 2] — the sum is \operatorname{lcm}(1,1) + \operatorname{lcm}(2, 2) = 1 + 2 = 3.  [2, 1] — the sum is \operatorname{lcm}(1,2) + \operatorname{lcm}(2, 1) = 2 + 2 = 4. 
212
1  2 1  
['constructive algorithms', 'greedy', 'number theory', '*800']