#include <bits/stdc++.h>
using namespace std;

#define int long long

void testcase()
{
	int N;
	cin >> N;

	string S;
	cin >> S;

	int max_count = 0, count = 0;
	for (int i = 0; i < S.size(); i++)
	{
		bool minus_ok = 0, zero_ok = 0, plus_ok = 0;
		for (int j = i; j < S.size(); j++)
		{
			if (S[j] == '-' && !zero_ok && !plus_ok)
				count++;

			if (S[j] == '0' && !plus_ok)
			{
				count++;
				zero_ok = 1;
			}

			if (S[j] == '+')
			{
				count++;
				plus_ok = 1;
			}
		}
		max_count = max(max_count, count);
		count = 0;
	}

	cout << max_count << '\n';
}

int32_t main()
{
	ios::sync_with_stdio(false);
	cin.tie(0);
	cout.tie(0);

	testcase();
	return 0;
}