a=str(input());ans=0
for i in range(len(a)//2):
    if a[i]!=a[len(a)-i-1]:
        ans+=1
print(ans)
ca1276164dc99fb663a3529be0d6ff0d3ead8e99
<mask token>

<mask token>
for i in range(len(a) // 2):
    if a[i] != a[len(a) - i - 1]:
        ans += 1
print(ans)

a = str(input())
ans = 0
for i in range(len(a) // 2):
    if a[i] != a[len(a) - i - 1]:
        ans += 1
print(ans)

a=str(input());ans=0
for i in range(len(a)//2):
    if a[i]!=a[len(a)-i-1]:
        ans+=1
print(ans)