a = input()
b = input()
c = a + b

ans, h = 0, 1

for i in range(len(c)-1):
    if c[i] == "o" and c[i+1] == "x":
        h = 1
    elif c[i] == "o" and c[i+1] == "o":
        h += 1
    ans = max(ans, h)

print(ans)