题解 | 穷哈哈~

n = int(input())
s = input()
max = 0
c = 0
q = None
for i in s:
    if i != 'a' and i != 'h':
        q = None
        continue
    if q is None:
        c = 1
        q = i
    else:
        if i != q:
            c = c + 1
            q = i
        else:
            c = 1
            q = i
    if c > max:
        max = c
print(max)