Week1 = str(input())
Week2 = str(input())
count1 = 0
count2 = 0
maxCount1 = 1
maxCount2 = 1

for i in range(len(Week1)):
    if(str(Week1) == "〇"):
        count1 += 1
    else:
        if(maxCount1 < count1):
            maxCount1 = count1
        count1 = 0

for i in range(len(Week2)):
    if(str(Week2) == "〇"):
        count2 += 1
    else:
        if(maxCount2 < count2):
            maxCount2 = count2
        count2 = 0

if(maxCount1 >= maxCount2):
    print(maxCount1)
else:
    print(maxCount2)