Alya has been given a hard problem. Unfortunately, she is too busy running for student council. Please solve this problem for her.
Given an integer $n$, construct a permutation $p$ of integers $1, 2, \ldots, n$ that maximizes the value of $k$ (which is initially $0$) after the following process.
Perform $n$ operations, on the $i$-th operation ($i=1, 2, \dots, n$),
- If
$i$is odd,$k=k\,\&\,p_i$, where$\&$denotes the bitwise AND operation. - If
$i$is even,$k=k\,|\,p_i$, where$|$denotes the bitwise OR operation.
Input
The first line contains a single integer $t$ ($1\le t\le 500$) — the number of test cases.
The only line of each test case contains a single integer $n$ ($5\le n\le 2 \cdot 10^5$) — the length of the permutation.
It is guaranteed that the sum of $n$ over all test cases does not exceed $2 \cdot 10^5$.
Output
For each test case, output the maximum value of $k$ in the first line and output the permutation $p_1, p_2,\ldots, p_n$ in the second line.
If there are multiple such permutations, output any.
Note
For the first test case, the value of $k$ is determined as follows:
$k = 0$ initially.
- On the
$1$st operation,$1$is odd, so Alya sets$k$to be$k\&p_1 = 0\&2 = 0$. - On the
$2$nd operation,$2$is even, so Alya sets$k$to be$k|p_2 = 0|1 = 1$. - On the
$3$rd operation,$3$is odd, so Alya sets$k$to be$k\&p_3 = 1\&3 = 1$. - On the
$4$th operation,$4$is even, so Alya sets$k$to be$k|p_4 = 1|4 = 5$. - On the
$5$th operation,$5$is odd, so Alya sets$k$to be$k\&p_5 = 5\&5 = 5$.
The final value of $k$ is $5$. It can be shown that the final value of $k$ is at most $5$ for all permutations of length $5$. Another valid output is $[2, 3, 1, 4, 5]$.
For the second test case, the final value of $k$ is $7$. It can be shown that the final value of $k$ is at most $7$ for all permutations of length $6$. Other valid outputs include $[2, 4, 1, 6, 3, 5]$ and $[5, 2, 6, 1, 3, 4]$.
样例
6
5
6
7
8
9
10
5
2 1 3 4 5
7
1 2 4 6 5 3
7
2 4 5 1 3 6 7
15
2 4 5 1 3 6 7 8
9
2 4 5 6 7 1 3 8 9
15
1 2 3 4 5 6 8 10 9 7
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