#P1905F. Field Should Not Be Empty

    ID: 8907 Type: RemoteJudge 2000ms 256MiB Tried: 0 Accepted: 0 Difficulty: (None) Uploaded By: Tags>brute forcedata structuresdivide and conquer

Field Should Not Be Empty

No submission language available for this problem.

Description

You are given a permutation^{\dagger} pp of length nn.

We call index xx good if for all y<xy < x it holds that py<pxp_y < p_x and for all y>xy > x it holds that py>pxp_y > p_x. We call f(p)f(p) the number of good indices in pp.

You can perform the following operation: pick 22 distinct indices ii and jj and swap elements pip_i and pjp_j.

Find the maximum value of f(p)f(p) after applying the aforementioned operation exactly once.

^{\dagger}A permutation of length nn is an array consisting of nn distinct integers from 11 to nn in arbitrary order. For example, [2,3,1,5,4][2,3,1,5,4] is a permutation, but [1,2,2][1,2,2] is not a permutation (22 appears twice in the array), and [1,3,4][1,3,4] is also not a permutation (n=3n=3 but there is 44 in the array).

Each test consists of multiple test cases. The first line of contains a single integer tt (1t21041 \le t \le 2 \cdot 10^4) — the number of test cases. The description of the test cases follows.

The first line of each test case contains a single integer nn (2n21052 \le n \le 2 \cdot 10^5) — the length of the permutation pp.

The second line of each test case contain nn distinct integers p1,p2,,pnp_1, p_2, \ldots, p_n (1pin1 \le p_i \le n) — the elements of the permutation pp.

It is guaranteed that sum of nn over all test cases does not exceed 21052 \cdot 10^5.

For each test case, output a single integer — the maximum value of f(p)f(p) after performing the operation exactly once.

Input

Each test consists of multiple test cases. The first line of contains a single integer tt (1t21041 \le t \le 2 \cdot 10^4) — the number of test cases. The description of the test cases follows.

The first line of each test case contains a single integer nn (2n21052 \le n \le 2 \cdot 10^5) — the length of the permutation pp.

The second line of each test case contain nn distinct integers p1,p2,,pnp_1, p_2, \ldots, p_n (1pin1 \le p_i \le n) — the elements of the permutation pp.

It is guaranteed that sum of nn over all test cases does not exceed 21052 \cdot 10^5.

Output

For each test case, output a single integer — the maximum value of f(p)f(p) after performing the operation exactly once.

Sample Input 1

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

Sample Output 1

3
5
2
3
2

Note

In the first test case, p=[1,2,3,4,5]p = [1,2,3,4,5] and f(p)=5f(p)=5 which is already maximum possible. But must perform the operation anyway. We can get f(p)=3f(p)=3 by choosing i=1i=1 and j=2j=2 which makes p=[2,1,3,4,5]p = [2,1,3,4,5].

In the second test case, we can transform pp into [1,2,3,4,5][1,2,3,4,5] by choosing i=1i=1 and j=2j=2. Thus f(p)=5f(p)=5.