Vasya has a pile, that consists of some number of stones. $$$n$$$ times he either took one stone from the pile or added one stone to the pile. The pile was non-empty before each operation of taking one stone from the pile.

You are given $$$n$$$ operations which Vasya has made. Find the minimal possible number of stones that can be in the pile after making these operations.

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.

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 $$$3$$$.

A pile of stones

Examples