S=list(eval(input()))

T=list(eval(input()))

counter=0

for i in range(len(S)):

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

        counter+=1

print(counter)
S=eval(input())

T=eval(input())

counter=0

for i in range(len(S)):

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

        counter+=1

print(counter)
S = list(eval(input()))
T = list(eval(input()))
counter = 0
for i in range(len(S)):
    if S[i] != T[i]:
        counter += 1
print(counter)

S = eval(input())
T = eval(input())
counter = 0
for i in range(len(S)):
    if S[i] != T[i]:
        counter += 1
print(counter)

-S = list(eval(input())) -T = list(eval(input())) +S = eval(input()) +T = eval(input())