from itertools import groupby

c1 = input()
c2 = input()
C = c1 + c2

groups = groupby(C)
result = [(label, sum(1 for _ in group)) for label, group in groups]
O = []
for i in result:
    if 'o' in i:
        O.append(i)


if O == []:
    print(0)
else:
    print(max(O)[1])