n = int(input())
s = input()
maxl = curl = 0
for i in range(n):
    if s[i] in 'ah':#当前字符是笑声
        if i==0:#当前字符是开始字符
            curl = 1
        elif s[i]!=s[i-1] and s[i-1] in 'ah':#当前字符是笑声,且与前一个笑声字符不同
            curl += 1
        else:
            curl = 1
    else:#当前字符不是笑声
        curl = 0
    maxl = max(maxl,curl)#最长笑声长度
print(maxl)