def main():
    list1 = list(input())
    list2 = list(input())
    concat_list = list1 + list2

    max_holidays = 0
    count = 0
    for e in concat_list:
        if e == "o":
            count += 1
        else:
            if count > max_holidays:
                max_holidays = count
            count = 0
    if max_holidays < count:
        max_holidays = count

    print(max_holidays)

if __name__ == '__main__':
    main()