Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.
If you've seen these problems, a virtual contest is not for you - solve these problems in the archive.
If you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.
Never use someone else's code, read the tutorials or communicate with other person during a virtual contest.

No tag edit access

The problem statement has recently been changed. View the changes.

×
F. Strange Sort

time limit per test

2 secondsmemory limit per test

512 megabytesinput

standard inputoutput

standard outputYou have a permutation: an array $$$a = [a_1, a_2, \ldots, a_n]$$$ of distinct integers from $$$1$$$ to $$$n$$$. The length of the permutation $$$n$$$ is odd.

Consider the following algorithm of sorting the permutation in increasing order.

A helper procedure of the algorithm, $$$f(i)$$$, takes a single argument $$$i$$$ ($$$1 \le i \le n-1$$$) and does the following. If $$$a_i > a_{i+1}$$$, the values of $$$a_i$$$ and $$$a_{i+1}$$$ are exchanged. Otherwise, the permutation doesn't change.

The algorithm consists of iterations, numbered with consecutive integers starting with $$$1$$$. On the $$$i$$$-th iteration, the algorithm does the following:

- if $$$i$$$ is odd, call $$$f(1), f(3), \ldots, f(n - 2)$$$;
- if $$$i$$$ is even, call $$$f(2), f(4), \ldots, f(n - 1)$$$.

It can be proven that after a finite number of iterations the permutation will be sorted in increasing order.

After how many iterations will this happen for the first time?

Input

Each test contains multiple test cases. The first line contains the number of test cases $$$t$$$ ($$$1 \le t \le 10^4$$$). Description of the test cases follows.

The first line of each test case contains a single integer $$$n$$$ ($$$3 \le n \le 2 \cdot 10^5 - 1$$$; $$$n$$$ is odd) — the length of the permutation.

The second line contains $$$n$$$ distinct integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \le a_i \le n$$$) — the permutation itself.

It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5 - 1$$$.

Output

For each test case print the number of iterations after which the permutation will become sorted in increasing order for the first time.

If the given permutation is already sorted, print $$$0$$$.

Example

Input

3 3 3 2 1 7 4 5 7 1 3 2 6 5 1 2 3 4 5

Output

3 5 0

Note

In the first test case, the permutation will be changing as follows:

- after the $$$1$$$-st iteration: $$$[2, 3, 1]$$$;
- after the $$$2$$$-nd iteration: $$$[2, 1, 3]$$$;
- after the $$$3$$$-rd iteration: $$$[1, 2, 3]$$$.

In the second test case, the permutation will be changing as follows:

- after the $$$1$$$-st iteration: $$$[4, 5, 1, 7, 2, 3, 6]$$$;
- after the $$$2$$$-nd iteration: $$$[4, 1, 5, 2, 7, 3, 6]$$$;
- after the $$$3$$$-rd iteration: $$$[1, 4, 2, 5, 3, 7, 6]$$$;
- after the $$$4$$$-th iteration: $$$[1, 2, 4, 3, 5, 6, 7]$$$;
- after the $$$5$$$-th iteration: $$$[1, 2, 3, 4, 5, 6, 7]$$$.

In the third test case, the permutation is already sorted and the answer is $$$0$$$.

Codeforces (c) Copyright 2010-2021 Mike Mirzayanov

The only programming contests Web 2.0 platform

Server time: Dec/02/2021 10:57:56 (g2).

Desktop version, switch to mobile version.

Supported by

User lists

Name |
---|