CF1697A.Parkway Walk

You are walking through a parkway near your house. The parkway has $n+1$ benches in a row numbered from $1$ to $n+1$ from left to right. The distance between the bench $i$ and $i+1$ is $a_i$ meters.

Initially, you have $m$ units of energy. To walk $1$ meter of distance, you spend $1$ unit of your energy. You can't walk if you have no energy. Also, you can restore your energy by sitting on benches (and this is the only way to restore the energy). When you are sitting, you can restore any integer amount of energy you want (if you sit longer, you restore more energy). Note that the amount of your energy can exceed $m$.

Your task is to find the minimum amount of energy you have to restore (by sitting on benches) to reach the bench $n+1$ from the bench $1$ (and end your walk).

You have to answer $t$ independent test cases.

你正在家附近的林荫道上行走。这条林荫道上从左到右依次排列着 $n+1$ 张长椅，编号为 $1$ 到 $n+1$。第 $i$ 张长椅与第 $i+1$ 张长椅之间的距离为 $a_i$ 米。

初始时，你拥有 $m$ 单位能量。每行走 $1$ 米的距离，你将消耗 $1$ 单位能量。当你能量为 $0$ 时，将无法继续行走。此外，你只能通过坐在长椅上来恢复能量（这是唯一恢复能量的方式）。当你坐在长椅上时，你可以恢复任意整数单位的能量（坐得越久，恢复的能量越多）。注意：你的能量总量可以超过 $m$。

你的任务是：求出从第 $1$ 张长椅出发，最终到达第 $n+1$ 张长椅（并结束行走）所需恢复的最小能量总量（即坐在长椅上所恢复的能量总和）。

你需要回答 $t$ 个相互独立的测试用例。

The first line of the input contains one integer $t$ ($1 \le t \le 100$) — the number of test cases. Then $t$ test cases follow.

The first line of the test case contains two integers $n$ and $m$ ($1 \le n \le 100$; $1 \le m \le 10^4$).

The second line of the test case contains $n$ integers $a_1, a_2, \ldots, a_n$ ($1 \le a_i \le 100$), where $a_i$ is the distance between benches $i$ and $i+1$.

输入的第一行包含一个整数 $t$（$1 \le t \le 100$），表示测试用例的数量。随后是 $t$ 个测试用例。

每个测试用例的第一行包含两个整数 $n$ 和 $m$（$1 \le n \le 100$；$1 \le m \le 10^4$）。

每个测试用例的第二行包含 $n$ 个整数 $a_1, a_2, \ldots, a_n$（$1 \le a_i \le 100$），其中 $a_i$ 表示第 $i$ 个长椅与第 $i+1$ 个长椅之间的距离。

For each test case, print one integer — the minimum amount of energy you have to restore (by sitting on benches) to reach the bench $n+1$ from the bench $1$ (and end your walk) in the corresponding test case.

对于每个测试用例，输出一个整数——即在对应的测试用例中，从长椅 $1$ 出发到达长椅 $n+1$（并结束行走）所需恢复的最小能量值（通过坐在长椅上恢复）。

In the first test case of the example, you can walk to the bench $2$, spending $1$ unit of energy, then restore $2$ units of energy on the second bench, walk to the bench $3$, spending $2$ units of energy, restore $1$ unit of energy and go to the bench $4$.

In the third test case of the example, you have enough energy to just go to the bench $6$ without sitting at all.

在示例的第一个测试用例中，你可以步行至长椅 $2$，消耗 $1$ 单位能量，然后在第二张长椅上恢复 $2$ 单位能量，再步行至长椅 $3$，消耗 $2$ 单位能量，恢复 $1$ 单位能量，最后前往长椅 $4$。

在示例的第三个测试用例中，你的能量足够直接前往长椅 $6$，而无需在任何长椅上休息。