S, T = [eval(input()) for _ in range(2)]

cnt = 0

for i, c in enumerate(S):

    if c != T[i]:

        cnt += 1



print(cnt)
S, T = [eval(input()) for _ in range(2)]

print((sum(s != t for s, t in zip(S, T))))
S, T = [eval(input()) for _ in range(2)]
cnt = 0
for i, c in enumerate(S):
    if c != T[i]:
        cnt += 1
print(cnt)

S, T = [eval(input()) for _ in range(2)]
print((sum(s != t for s, t in zip(S, T))))

-cnt = 0 -for i, c in enumerate(S): -    if c != T[i]: -        cnt += 1 -print(cnt) +print((sum(s != t for s, t in zip(S, T))))