An arbitrary array of integers $b$ of length $m$ is considered awesome if for all $i$ ($1 \le i \lt m$):
- if
$i$is odd then$b_i \lt b_{i + 1}$holds. - if
$i$is even then$b_i \gt b_{i + 1}$holds.
In other words, the following inequality is true: $b_1 \lt b_2 \gt b_3 \lt b_4 \ldots$
You are given an array of positive integers $a$ of length $n$. You may do either of the following operations any number of times, in any order:
- operation
$1$: select an integer$i$($1 \le i \le n$) and do:$a_i := \max(a_1,\ldots,a_i)$, that is, replace$a_i$with the prefix max up to$i$. - operation
$2$: select an integer$i$($1 \le i \le n$) and then decrease$a_i$by$1$.
Determine the minimum number of times you need to do operation $2$ to make $a$ awesome. Note that you do not need to minimise the number of times you perform operation $1$.
Input
Each test contains multiple test cases. The first line contains the number of test cases $t$ ($1 \le t \le 10^4$). The description of the test cases follows.
The first line of each test case contains an integer $n$ ($2 \le n \le 2 \cdot 10^5$) — the length of the array $a$.
The second line of each test case contains $n$ integers $a_1,a_2,\ldots,a_n$ ($1 \le a_i \le 10^9$).
The sum of $n$ across all test cases does not exceed $2 \cdot 10^5$.
Output
For each testcase, output the minimum cost to make $a$ awesome.
Note
In the first test case, the array is already awesome so no operations need to be done.
In the second test case, $a$ can be made awesome as follows:
- use operation
$2$and decrease$a_1$by$1$.$[\color{red}3, 3, 2, 1] \rightarrow [\color{red}2, 3, 2, 1]$. - use operation
$1$and change$a_4$to$\max(2, 3, 2, 1) = 3$.$[2, 3, 2, \color{red}1] \rightarrow [2, 3, 2, \color{red}3]$.
$[2, 3, 2, 3]$ is awesome as $2 \lt 3 \gt 2 \lt 3$. It can be proven that this is the minimum number of times operation $2$ needs to be performed.
样例
7
5
1 4 2 5 3
4
3 3 2 1
5
6 6 6 6 6
7
1 2 3 4 5 6 7
3
3 2 1
2
1 2
9
65 85 19 53 21 79 92 29 96
0
1
3
6
1
0
13
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