A pile of stones

Description:

Input:

The first line contains one positive integer $$$n$$$ — the number of operations, that have been made by Vasya ($$$1 \leq n \leq 100$$$).

The next line contains the string $$$s$$$, consisting of $$$n$$$ symbols, equal to "-" (without quotes) or "+" (without quotes). If Vasya took the stone on $$$i$$$-th operation, $$$s_i$$$ is equal to "-" (without quotes), if added, $$$s_i$$$ is equal to "+" (without quotes).

Output:

Print one integer — the minimal possible number of stones that can be in the pile after these $$$n$$$ operations.

Sample Input:

3
---

Sample Output:

0

Sample Input:

4
++++

Sample Output:

4

Sample Input:

2
-+

Sample Output:

1

Sample Input:

5
++-++

Sample Output:

3

Note:

In the first test, if Vasya had $$$3$$$ stones in the pile at the beginning, after making operations the number of stones will be equal to $$$0$$$. It is impossible to have less number of piles, so the answer is $$$0$$$. Please notice, that the number of stones at the beginning can't be less, than $$$3$$$, because in this case, Vasya won't be able to take a stone on some operation (the pile will be empty).

In the second test, if Vasya had $$$0$$$ stones in the pile at the beginning, after making operations the number of stones will be equal to $$$4$$$. It is impossible to have less number of piles because after making $$$4$$$ operations the number of stones in the pile increases on $$$4$$$ stones. So, the answer is $$$4$$$.

In the third test, if Vasya had $$$1$$$ stone in the pile at the beginning, after making operations the number of stones will be equal to $$$1$$$. It can be proved, that it is impossible to have less number of stones after making the operations.

In the fourth test, if Vasya had $$$0$$$ stones in the pile at the beginning, after making operations the number of stones will be equal to $$$3$$$.