s = input().rstrip()
t = input().rstrip()
n = 0
for i in range(len(s)):
    if s[i] != t[i]:
        n += 1
print(n)

e9da8a8b7ed0c42201f564c4de8a5e6439efb4d9
<mask token>

<mask token>
for i in range(len(s)):
    if s[i] != t[i]:
        n += 1
print(n)

s = input().rstrip()
t = input().rstrip()
n = 0
for i in range(len(s)):
    if s[i] != t[i]:
        n += 1
print(n)
