S = str(eval(input()))

T = str(eval(input()))

N = 0

Count = []

for i in range(len(S)):

    if S[N] != T[N]:

        Count.append(1)

    N += 1

print((len(Count)))
s = str(eval(input()))

t = str(eval(input()))

count = 0

for i in range(len(s)):

    if s[i] != t[i]:

        count +=1

print(count)
S = str(eval(input()))
T = str(eval(input()))
N = 0
Count = []
for i in range(len(S)):
    if S[N] != T[N]:
        Count.append(1)
    N += 1
print((len(Count)))

s = str(eval(input()))
t = str(eval(input()))
count = 0
for i in range(len(s)):
    if s[i] != t[i]:
        count += 1
print(count)

-S = str(eval(input())) -T = str(eval(input())) -N = 0 -Count = [] -for i in range(len(S)): -    if S[N] != T[N]: -        Count.append(1) -    N += 1 -print((len(Count))) +s = str(eval(input())) +t = str(eval(input())) +count = 0 +for i in range(len(s)): +    if s[i] != t[i]: +        count += 1 +print(count)