W1 = input()
W2 = input()

def solve(str1, str2):
    maxh = 0
    cstr = str1 + str2
    for i in range(len(cstr)):
        if cstr[i] == "o":
            temp = 1
            for j in range(i+1, len(cstr)):
                if cstr[j] == "x":
                    break
                else:
                    temp += 1
            if maxh < temp:
                maxh = temp
    return maxh
solve

print(solve(W1, W2))