t = list(eval(input()))

s = list(eval(input()))

cnt = 0

for i in range(len(s)):

    if t[i]!=s[i]: cnt+=1

print(cnt)
s = eval(input())

t = eval(input())

print((sum(1 for x,y in zip(s,t) if x!=y)))
t = list(eval(input()))
s = list(eval(input()))
cnt = 0
for i in range(len(s)):
    if t[i] != s[i]:
        cnt += 1
print(cnt)

s = eval(input())
t = eval(input())
print((sum(1 for x, y in zip(s, t) if x != y)))

-t = list(eval(input())) -s = list(eval(input())) -cnt = 0 -for i in range(len(s)): -    if t[i] != s[i]: -        cnt += 1 -print(cnt) +s = eval(input()) +t = eval(input()) +print((sum(1 for x, y in zip(s, t) if x != y)))