S = input()
S += input()

_max = 0
i = 0
while i < len(S):
    if S[i] == 'x':
        i += 1
        continue
    l = i
    while l < len(S) and S[l] == 'o':
        l += 1
    count = l - i
    if count > _max:
        _max = count
    i = l
print(_max)