#D2943. Let's Go Hiking
Let's Go Hiking
Let's Go Hiking
On a weekend, Qingshan suggests that she and her friend Daniel go hiking. Unfortunately, they are busy high school students, so they can only go hiking on scratch paper.
A permutation p is written from left to right on the paper. First Qingshan chooses an integer index x (1≤ x≤ n) and tells it to Daniel. After that, Daniel chooses another integer index y (1≤ y≤ n, y ≠ x).
The game progresses turn by turn and as usual, Qingshan moves first. The rules follow:
- If it is Qingshan's turn, Qingshan must change x to such an index x' that 1≤ x'≤ n, |x'-x|=1, x'≠ y, and p_{x'}<p_x at the same time.
- If it is Daniel's turn, Daniel must change y to such an index y' that 1≤ y'≤ n, |y'-y|=1, y'≠ x, and p_{y'}>p_y at the same time.
The person who can't make her or his move loses, and the other wins. You, as Qingshan's fan, are asked to calculate the number of possible x to make Qingshan win in the case both players play optimally.
Input
The first line contains a single integer n (2≤ n≤ 10^5) — the length of the permutation.
The second line contains n distinct integers p_1,p_2,...,p_n (1≤ p_i≤ n) — the permutation.
Output
Print the number of possible values of x that Qingshan can choose to make her win.
Examples
Input
5 1 2 5 4 3
Output
1
Input
7 1 2 4 6 5 3 7
Output
0
Note
In the first test case, Qingshan can only choose x=3 to win, so the answer is 1.
In the second test case, if Qingshan will choose x=4, Daniel can choose y=1. In the first turn (Qingshan's) Qingshan chooses x'=3 and changes x to 3. In the second turn (Daniel's) Daniel chooses y'=2 and changes y to 2. Qingshan can't choose x'=2 because y=2 at this time. Then Qingshan loses.
inputFormat
Input
The first line contains a single integer n (2≤ n≤ 10^5) — the length of the permutation.
The second line contains n distinct integers p_1,p_2,...,p_n (1≤ p_i≤ n) — the permutation.
outputFormat
Output
Print the number of possible values of x that Qingshan can choose to make her win.
Examples
Input
5 1 2 5 4 3
Output
1
Input
7 1 2 4 6 5 3 7
Output
0
Note
In the first test case, Qingshan can only choose x=3 to win, so the answer is 1.
In the second test case, if Qingshan will choose x=4, Daniel can choose y=1. In the first turn (Qingshan's) Qingshan chooses x'=3 and changes x to 3. In the second turn (Daniel's) Daniel chooses y'=2 and changes y to 2. Qingshan can't choose x'=2 because y=2 at this time. Then Qingshan loses.
样例
5
1 2 5 4 3
1
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