#include <cstdio>
#include <cstring>
#include <cstdlib>
#include <cassert>
#include <cctype>
#include <vector>
#include <iostream>
#include <string>
#include <bitset>
using namespace std;

const int MAXN = 100000;

void solve()
{
    int n;
    assert(scanf("%d", &n) == 1 && 1 <= n && n <= MAXN);
    if (n & 1) {
        for (int i = 0; i < n - 3; ++ i) {
            printf("%d ", (i ^ 1) + 1);
        }
        printf("%d %d %d\n", n - 1, n, n - 2);
    } else {
        for (int i = 0; i < n; ++ i) {
            printf("%d ", (i ^ 1) + 1);
        }
        puts("");
    }
}

int main()
{
    int tests;
    for (assert(scanf("%d", &tests) == 1 && 1 <= tests && tests <= 10); tests --; ) {
        solve();
    }
    return 0;
}