import sys
import math
from collections import Counter
import bisect

input = sys.stdin.readline

# author: nemesis-lance

# Started solving: 2025-07-25 23:39:03
# ------------------------------------
# </> META COGNITION >/<

def solve():
    n = int(input())
    s = input().strip()
    a = [[0,0] for i in range(n)]
    count = 1
    for i in range(n):
        a[i][0] = count
        if s[i] == '-':
            count += 1
        
    
    # print(a)
    count = 1
    for i in range(n-1,-1,-1):
        a[i][1] = count
        if s[i] == '+':
            count += 1
    # print(a)
    max_sum = 0
    for i in range(n):
        sum = a[i][0] + a[i][1] - 1 
        if sum > max_sum:
            max_sum = sum
    print(max_sum)


















solve()