#include <iostream>

using namespace std;
using ll = long long;

int N;
string S;
int A[303030], B[303030];
int main(void){
	ios::sync_with_stdio(false);
	cin.tie(nullptr);

	cin >> N >> S;
	for(int i = 0;i < N;i++){
		A[i + 1] = A[i] + (S[i] == '-');
	}
	for(int i = N - 1;i >= 0;i--){
		B[i] = B[i + 1] + (S[i] == '+');
	}
	int ans = 0;
	for(int i = 0;i < N;i++){
		ans = max(A[i] + 1 + B[i + 1], ans);
	}
	cout << ans << endl;
	return 0;
}