c1 = input()
c2 = input()

day = c1+c2

isContinue = False
cnt_now = 0
max_cnt = 0

for char in day:
    if char == 'x':
        if isContinue:
            isContinue = False
            if max_cnt <= cnt_now:
                max_cnt = cnt_now
            cnt_now = 0

    if char == 'o':
        isContinue = True
        cnt_now += 1

if cnt_now >= max_cnt:
    print(cnt_now)
else:
    print(max_cnt)