Problem:
 Score : 200 points    Problem Statement  Takahashi loves palindromes. Non-palindromic strings are unacceptable to him. Each time he hugs a string, he can change one of its characters to any character of his choice.  Given is a string S . Find the minimum number of hugs needed to make S palindromic.      Constraints   S is a string consisting of lowercase English letters.  The length of S is between 1 and 100 (inclusive).         Input  Input is given from Standard Input in the following format:  S       Output  Print the minimum number of hugs needed to make S palindromic.        Sample Input 1 redcoder      Sample Output 1 1  For example, we can change the fourth character to o and get a palindrome redooder .       Sample Input 2 vvvvvv      Sample Output 2 0  We might need no hugs at all.       Sample Input 3 abcdabc      Sample Output 3 2

Solution (Python):
s = list(input())

a = list(reversed(s))
cnt = 0
for i in range(len(s)):
  if s[i] != a[i]:
    cnt += 1
print(cnt//2)

Solution (Python):
s = input()

len_s = len(s)

total = 0

for i in range((len_s + 1) // 2):
    if s[i] != s[len_s - i - 1]:
        total += 1

print(total)

Solution (Python):


s = input()
n = len(s)
cnt = 0

for i in range(int(n/2)):
    if s[i] != s[-(i+1)]:
        cnt += 1
print(cnt)

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

Solution (Python):
a_str = input()
b_str = a_str[::-1]
c_list= []

for i in range(0,len(a_str)):
    if a_str[i] != b_str[i]:
        c_list.append(a_str[i])

print(int(len(c_list)/2))

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

Solution (Python):
S = input()

if len(S) % 2 == 0:
  sSize = len(S) // 2
else :
  sSize = (len(S)-1) // 2

count = 0
for i in range(sSize):
  if S[i] != S[-1*(i+1)]:
    count += 1

print(count)

Solution (Python):
s = input()
reverse_s = s[::-1]

ans = 0
for i in range(len(s) // 2):
  if s[i] != reverse_s[i]:
    ans += 1
print(ans)

Solution (Python):
s = input()
ans = 0
for c0, c1 in zip(s[:len(s)//2], s[:-len(s)//2-1:-1]):
    if c0 != c1:
        ans += 1
print(ans)

Solution (Python):
str = input()

reverse_str = str[::-1]
num_changed = 0
repeat_time = len(str) / 2

i = 0
while i < repeat_time:
    if str[i] != reverse_str[i]:
        num_changed += 1
    i += 1

print(num_changed)

Solution (Python):
s = input()
c = 0
n = len(s)
if n%2 == 0:  
	for i in range(int(n/2)):
		if s[i]!=s[-(i+1)]:
			c = c + 1
else:
    for i in range(int((n+1)/2)):
        if s[i]!=s[-(i+1)]:
            c = c + 1
print(c)

Solution (Python):
S = str(input())

if len(S)%2 == 0:
    mid = int(len(S)/2)
else:
    mid = int(len(S)/2) + 1

left = S[:mid][::-1]
right = S[-mid:]

count = 0
for i in range(mid):
    if left[i] != right[i]:
        count = count + 1

print(count)

Solution (Python):
s = str(input())

cnt = 0

for i in range(len(s)//2):
    if s[i] != s[len(s)-1-i]:
        cnt += 1

print(cnt)

Solution (Python):
S = input()
l = len(S)
c = 0
for i in range(l // 2):
  if S[i] == S[l-i-1]:
    pass
  else:
    c +=1
print(c)

Solution (Python):
S = input()
ans = 0
for i in range(int(len(S)/2)):
	if S[i] != S[len(S)-i-1]:
		ans+=1
print(ans)

Solution (Python):
s=input()
c=0
for i in range(len(s)//2):
  if s[i]!=s[len(s)-i-1]:
    c+=1
print(c)

Solution (Python):
s = input()
cnt = 0
for i in range(len(s)//2):
  if s[i] != s[-i-1]:
    cnt += 1
print(cnt)

Solution (Python):
S = list(input())
ANS = 0
for i in range(len(S)//2):
    if S[i] != S[len(S)-i-1]:
        ANS += 1

print(ANS)

Solution (Python):
s = input()
h = int(len(s) / 2)
r = 0
for i in range(h):
    if not (s[i] == s[-1 - i]):
        r += 1
print(r)

Solution (Python):
s = input()
h = len(s)//2
A = s[:h]
B = s[-h:]
cnt = 0
for a,b in zip(A,B[::-1]):
	if a != b:
		cnt += 1
print(cnt)

Solution (Python):


S = input()
nhugs = 0

for i in range(len(S)//2):
    if S[i] != S[-(i+1)]:
        nhugs += 1

print(nhugs)

Solution (Python):
S = input()
count = 0
for i in range(int(len(S)/2)):
  if S[i] != S[len(S)-i-1]:
    count += 1
print(count)

Solution (Python):
s = input()
l = len(s)
h = l // 2
lis1 = []
lis2 = []
for i in range(0, h):
  lis1.append(s[i])
  lis2.append(s[-(i + 1)])
count = 0
for a, b in zip(lis1, lis2):
  if a != b:
    count += 1
print(count)

Solution (Python):
S = input()
n = len(S)

ans = 0
for i in range(n//2):
    if S[i] != S[-(i+1)]:
        ans += 1
print(ans)

Solution (Python):
string = input()

left = ""
right = ""

left = string[0:len(string)//2]
right = string[len(string)//2 + 1 if len(string)%2==1 else 0:len(string)]

right = right[::-1]

count = 0
for i in range(len(left)):
    count += 1 if left[i] != right[i] else 0

print(count)

Solution (Python):
a = input()
count = 0



list_before = []
list_after = []
for i in a:
	if count < len(a)/2:
		list_before.append(i)
	else:
		list_after.append(i)
	count += 1




l = int(len(a)/2)
count = 0
if len(list_before)-len(list_after) == 1:
	for i in range(l):
		if list_before[i] != list_after[l-1 - i]:
			list_before[i] = list_after[l-1 - i]
			count += 1
else: 
	for i in range(l):
		if list_before[i] != list_after[l-1 - i]:
			list_before[i] = list_after[l-1 - i]
			count += 1
		



print(count)

Solution (Python):
a = input()
count = 0



list_before = []
list_after = []
for i in a:
	if count < len(a)/2:
		list_before.append(i)
	else:
		list_after.append(i)
	count += 1




l = int(len(a)/2)
count = 0
if len(list_before)-len(list_after) == 1:
	for i in range(l):
		if list_before[i] != list_after[l-1 - i]:
			list_before[i] = list_after[l-1 - i]
			count += 1
else: 
	for i in range(l):
		if list_before[i] != list_after[l-1 - i]:
			list_before[i] = list_after[l-1 - i]
			count += 1
		



print(count)

Solution (Python):
s = input()
n = len(s)
cost = 0
for i in range(n // 2):
    cost += (s[i] != s[n - i - 1])
print(cost)

Solution (Python):
import math
str = input()
count = 0
loopnum = math.ceil(len(list(str))/2)
for i in range(loopnum):
  if list(str)[i] != list(str)[len(list(str)) - 1 - i]:
    count += 1

print(count)

Solution (Python):
S = list(input())
cou = 0
for i in range(len(S)//2):
	if S[i] != S[-i-1]:
		cou += 1
print(cou)

Solution (Python):
s = input().strip()
c = 0
for i in range(len(s)//2):
  if s[i] != s[-(i+1)]:
    c += 1
print(c)

Solution (Python):
s = input()
l = int ((len(s) - len(s) % 2) / 2)

count = 0
for i in range(l):
  if s[i] != s[-(i+1)]:
    count += 1

print(count)

Solution (Python):
s=input();
print(sum(a<b for a,b in zip(s,s[::-1])))

Solution (Python):
s=input();ans=0
for i in range(len(s)//2):
  ans+=int(s[i]!=s[len(s)-1-i])
print(ans)

Solution (Python):


s = input()
invs = ''.join(reversed(s))
count = 0
for i in range(len(s)):
    if s[i] != invs[i]:
        count += 1
    else:
        pass
print(count//2)

Solution (Python):
s = input()
l = len(s)
reset = 0

for i in range(l//2):
  if (s[i] == s[l-1-i]):
    pass
  else:
    reset += 1

print(reset)

Solution (Python):
S = input()
l = len(S)
i = 0
cnt = 0
while i < l/2 :
    if S[i] != S[l-1-i]:
        cnt += 1
    i += 1
print(cnt)

Solution (Python):
S = input()
l = len(S)
res = 0
for i in range(l//2):
  if(S[i] == S[l-1-i]):
    pass
  else:
    res += 1

print(res)

Solution (Python):
S = input()
N = len(S)
M = N//2
ans = 0
for i in range(M):
    if S[i] != S[N-1-i]:
        ans += 1
print(ans)

Solution (Python):
s = input()

sum = 0

length = len(s)
for i in range(length):
 if(s[0+i] != s[-1 - i]):
  sum += 1
 if(i+1 == int(length/2)):
  break

print(sum)

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

Solution (Python):
s = input()
count = 0
for i in range(len(s)//2):
    if s[i] != s[-i-1]:
        count += 1
    else:
        count = count
print(count)

Solution (Python):
S=input()
slen = len(S)
slen2 = slen // 2
ans=0
for i in range (slen2):
  if S[i] != S[-i-1]:
    ans += 1
print(ans)

Solution (Python):
S=input()
slen = len(S)
slen2 = slen // 2
ans=0
for i in range (slen2):
  if S[i] != S[-i-1]:
    ans += 1
print(ans)

Solution (Python):
s = input()
if len(s)%2 == 0:
    first = s[:len(s)//2]
    last2 = s[len(s)//2:]
    last = last2[::-1]
    count = 0
    for i in range(len(first)):
        if first[i] != last[i]:
            count += 1
    print(count)
else:
    first = s[:(len(s)-1)//2]
    last2 = s[(len(s)-1)//2:]
    last = last2[::-1]
    count = 0
    for i in range(len(first)):
        if first[i] != last[i]:
            count += 1
    print(count)

Solution (Python):
S = input()
ans = 0
if len(S) % 2 == 0:
    a = S[:len(S) // 2]
    b = S[len(S) // 2:]

    for i in range(len(a)):
        if a[i] != b[-i - 1]:
            ans += 1

else:
    mid = len(S) // 2
    a = S[:mid]
    b = S[mid:]
    for i in range(len(a)):
        if a[i] != b[-i - 1]:
            ans += 1

print(ans)

Solution (Python):
s = input()
count = 0
for x, y in zip(s, s[::-1]):
    if x != y:
        count += 1
print(count // 2)

Solution (Python):
S = input()
ans = 0
S_list = list(S)
for i in range(len(S)):
    if S_list[i] != S_list[len(S)-1-i]:
        S_list[i] = S_list[len(S)-1-i]
        ans += 1
print(ans)

Solution (Python):

s1 = input()
s2 = s1[::-1]

cnt = 0
for i in range(len(s1)):
  if (s1[i] != s2[i]):
    cnt += 1

print(int(cnt / 2))

Solution (Python):
def main():
    S = input()
    N = len(S)
    ans = 0
    for i in range(N//2):
        if S[i] != S[N-i-1]:
            ans += 1
    print(ans)


if __name__ == "__main__":
    main()

Solution (Python):
s = input()
n = len(s)//2
count = 0
for i in range(n):
    if s[i] != s[-1-i]:
        count += 1
print(count)

Solution (Python):
S = input()
cnt = 0
for i in range(len(S) // 2):
    if S[i] != S[- i - 1]:
        cnt += 1
print(cnt)

Solution (Python):
s=input()
re_s=s[::-1]
ans=0
for i in range(len(s)//2):
    if s[i]!=re_s[i]:
        ans+=1
print(ans)

Solution (Python):
s=input()

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

Solution (Python):
s = input()
mid = len(s) // 2
pre = s[:mid]
if len(s) % 2 == 0:
    aft = s[mid:]
    aft = aft[::-1]
else:
    aft = s[mid+1:]
    aft = aft[::-1]

dif = 0
for i in range(len(pre)):
    if pre[i] != aft[i]:
        dif += 1

print(dif)

Solution (Python):
s=input()
x=0
for i in range(len(s)//2):
  if s[i]!=s[-i-1]:x+=1
print(x)

Solution (Python):
S = list(input())

cnt = 0
if len(S)%2 == 0:
  for i in range(len(S)//2):
    if S[i] != S[len(S)-i-1]:
      cnt += 1
else:
  for i in range((len(S)-1)//2):
    if S[i] != S[len(S)-1-i]:
      cnt +=1
print(cnt)

Solution (Python):
S = list(input())


n = len(S)

cou = 0
for i in range(n//2):
    if S[i] != S[n-1-i]:
        S[n-1-i] = S[i]
        cou += 1
    else:
        continue

print(cou)

Solution (Python):
from sys import stdin
INF = float("inf")
IINF = 10 ** 18
MOD = 10 ** 9 + 7
s = str(stdin.readline().rstrip())
l = len(s)//2

count = 0

for i in range(l):
    if s[i] == s[-1-i]:
        pass
    else:
        count += 1

print(count)

Solution (Python):

if __name__ == '__main__':
    s = input()
    k = int(len(s) / 2)
    k1 = len(s) - 1
    count = 0
    for i in range(k):
        if s[i] != s[k1-i]:
            count+=1
    print(count)

Solution (Python):
S=input()
L=[]
R=[]
count=0
for i in range(len(S)):
    if i<=(len(S)+(2-1))//2-1:
        L.append(S[i])
        R.append(S[-i-1])
for i in range(len(L)):
    if L[i]==R[i]:
        count=count
    else:
        count+=1
print(count)

Solution (Python):
S = list(input())
Slen = len(S)
count = 0

for i in range(Slen//2):
    if S[i] != S[Slen-1-i]:
        count += 1

print(count)

Solution (Python):
S = input()
N = len(S)
ans = 0
for i in range(N//2):
    ans += S[i] != S[N-1-i]
print(ans)

Solution (Python):
s = input()

N = len(s)
if N%2 == 1:
    harf = N//2
    mae = s[:harf]
    usi = s[harf+1:][::-1]
else:
    harf = N//2
    mae = s[:harf]
    usi = s[harf:][::-1]

ans = 0
for i in range(harf):
    if mae[i] != usi[i]:
        ans += 1

print(ans)

Solution (Python):
S = str(input())
count = 0
for i in range(len(S)//2):
    if S[i]!=S[(i+1)*(-1)]:
        count += 1
print(count)

Solution (Python):
s = input()
s_list = list(s)
num = len(s_list)//2
result = 0
for i in range(num):
  if s_list[i] != s_list[-i-1]:
    result += 1
    s_list[-i-1] =s_list[i] 
print(result)

Solution (Python):
k = list(input())

if len(k) == 1:
    print(0)
elif len(k) == 2:
    if k[0] == k[1]:
        print(0)
    else:
        print(1)

elif len(k) % 2 == 0:
    count = 0
    for i in range(len(k)//2):
        if k[i] != k[len(k)-1-i]:
            count += 1
    print(count)

elif len(k) % 2 == 1:
    count = 0
    for i in range(len(k)//2):
        if k[i] != k[len(k)-1-i]:
            count += 1
    print(count)

Solution (Python):



s = input()


count = 0

i = 0
j = len(s) - 1
while True:
    if i >= j:
        break
    
    if s[i] != s[j]:
        count += 1
    
    i += 1
    j -= 1


print(count)

Solution (Python):


S = input()
num_hug = 0

s1 = S[:len(S)//2]  
s2x = list(S[len(S)//2:]) 

for c in s1:
    if c != s2x.pop():
        num_hug += 1
        
print(num_hug)

Solution (Python):
s =input()
cnt=0
for i,j in zip(s, s[::-1]):
    if i!=j:
        cnt+=1
print(cnt//2)

Solution (Python):
c=input()
a=list(c)
a_r=reversed(a)
b=[x==y for(x,y) in zip(a,a_r)].count(False)
print(b//2)

Solution (Python):
s=input();l=len(s)//2;c=0
for i in range(l):
  if s[i]!=s[-i-1]:
    c+=1
print(c)

Solution (Python):
s = input()
t = int(len(s) / 2)
count = 0
for i in range(t):
    if s[i] != s[-i-1]:
        count += 1

print(count)

Solution (Python):
S = input()
i = 0
j = len(S)-1
k = 0
while i<len(S)/2:
    if S[i] != S[j]:
        k = k+1
    i = i+1
    j = j-1
print(k)

Solution (Python):
S = input()
N = len(S)
i = 0
min_count = 0
while i < (N-1) - i:
    if S[i] != S[(N-1) - i]:
       S[(N-1) - i] == S[i]
       min_count += 1
    i += 1

print(min_count)

Solution (Python):
s = input()

c = 0
for i in range(len(s)//2):
  if s[i] != s[-(i+1)]:
    c += 1
print(c)

Solution (Python):
n = input()

ans=0
for a, b in zip(n, n[::-1]):
    if a != b:
        ans += 1

print(ans//2)

Solution (Python):
s=input()
print(sum(a<b for a,b in zip(s,s[::-1])))

Solution (Python):
S=input()
length=len(S)
d=0
counter=0
while counter<length:
  if S[counter]==S[length-1-counter]:
    d+=0
    counter+=1
  else:
    d+=1
    counter+=1
print(int(d/2))

Solution (Python):
s = input()
print(sum(i != j for i,j in zip(s[:len(s)//2],reversed(s[round(len(s)/2):]))))

Solution (Python):
A = input()
A = list(A)
cnt = 0
A_len = len(A)

A_len_h = A_len // 2

for i in range(0, A_len_h):
    if A[i] != A[A_len - i - 1]:
        cnt += 1

print(cnt)

Solution (Python):
S = input()
n = len(S)//2
cnt = 0
for i in range(n):
  if S[i] != S[len(S)-1-i]:
    cnt += 1
print(cnt)

Solution (Python):
text = input()
hug = 0
for i in range(len(text)):
  if text[i] != text[len(text) -1 - i]:
    hug += 1
print(hug // 2)

Solution (Python):
s = input()
 
count = 0
 
for i, c in enumerate(s):
  if i > (len(s) - 1) // 2:
    break
  if c != s[len(s) - 1 - i]:
    count += 1
    
print(count)

Solution (Python):
s=input()
print(sum(1 if s[i]!=s[-(i+1)] else 0 for i in range (len(s)//2)))

Solution (Python):
string = str(input())

cnt = 0
for forward, backward in zip(string[:len(string)//2+1], string[-1:len(string)//2-1:-1]):
  if forward != backward:
    cnt += 1

print(cnt)

Solution (Python):
s = input()
l = len(s)
cnt = 0
for i in range(int(l/2)):
  if s[i]!=s[l-1-i]:
    cnt +=1
    
print(cnt)

Solution (Python):
s = list(str(input()))

j = len(s)-1
i = 0
ans = 0
while(i < j):
  if s[i] != s[j] :
    ans += 1
    i += 1
    j -= 1
  else:
    i += 1
    j -= 1
    continue
print(ans)

Solution (Python):
s=input()
count=0
i=0
while i<(len(s) // 2):
	if s[i]!=s[-(i+1)]:
		count+=1
	i+=1
print(count)

Solution (Python):
s=input()
count=0

for i in range(len(s) // 2):
	if s[i]!=s[-(i+1)]:
		count+=1
print(count)

Solution (Python):
s = input()

le = len(s)

if le % 2 == 0: 
  mid = int(le / 2)
  s1 = s[:mid]
  s2 = s[mid:]
  count = 0
  for i in range(mid):
    tmp1 = s1[i]
    tmp2 = s2[len(s2) - 1 - i]
    if tmp1 != tmp2:
      count += 1
  print(count)
  exit()

mid  = le // 2
s1 = s[:mid]
s2 = s[mid + 1: ]
count = 0
for i in range(mid):
  tmp1 = s1[i]
  tmp2 = s2[len(s2) - 1 - i]
  if tmp1 != tmp2:
    count += 1
print(count)

Solution (Python):
n = input()
c = 0
for i in range(len(n)//2):
    if n[i] != n[-i-1]:
        c += 1
print(c)

Solution (Python):
word = list(input())

count = 0  

if len(word) % 2 == 0:  
  for i in range(0,int(len(word)/2)):
    if word[i] != word[int(len(word))-1-i]:
      count += 1    
  print(count)

else:
  for j in range(0,int((len(word)+1)/2-1)):
    if word[j] != word[int(len(word))-1-j]:
      count += 1
  print(count)

Solution (Python):
s = input()
  
ret = 0
for i in range(len(s)//2):
	if s[i] != s[-i-1]:
		ret = ret + 1
print(ret)

Solution (Python):
s = input()
print(sum(1 if s[i] != s[-(i+1)] else 0 for i in range(len(s)//2)))

Solution (Python):
S = input()
result = 0
for i in range(len(S)//2):
  if S[i] ==S[-1-i]:
    None
  else:
    result += 1
print(result)

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

Solution (Python):
x = input()
y = x[::-1]
count = 0
for c in range(len(x)):
    i = x[c]
    j = y[c]
    if i != j:
        count += 1
print(count//2)

Solution (Python):
str = input()

s = 0
e = len(str) - 1

count = 0

while s < e:

    if str[s] != str[e]:
        count += 1

    s += 1
    e -= 1

print(count)

Solution (Python):

import sys


def solve(S: str):
    N = len(S)
    count = 0
    if N == 1:
        pass
    else:
        for i in range(N//2):
            if S[i] != S[-1-i]:
                count += 1
    print(count)


def main():
    def iterate_tokens():
        for line in sys.stdin:
            for word in line.split():
                yield word
    tokens = iterate_tokens()
    S = next(tokens)  
    solve(S)

if __name__ == '__main__':
    main()

Solution (Python):
str = input()
lst = list(str)
count = 0

for i in range(int(len(lst)/2)):
  if lst[i] != lst[-i-1]:
    count += 1
  else:
    pass
print(count)

Solution (Python):
s = input()
from collections import deque

q = deque(list(s))

cnt = 0

while q:
	if len(q) == 1:
		q.pop()
	else:
		l = q.popleft()
		r = q.pop()
		if l != r:
			cnt += 1
print(cnt)

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

Solution (Python):
from collections import Counter,defaultdict,deque
from heapq import heappop,heappush,heapify
import sys,bisect,math,itertools,fractions,pprint
sys.setrecursionlimit(10**8)
mod = 10**9+7
mod2 = 998244353
INF = float('inf')
def inp(): return int(sys.stdin.readline())
def inpl(): return list(map(int, sys.stdin.readline().split()))
def inpln(n): return list(int(sys.stdin.readline()) for i in range(n))

s = input()
n = len(s)
res = 0
for i in range(n//2):
    if s[i] != s[n-i-1]:
        res += 1
print(res)

Solution (Python):



def main():
    s = input()
    ans = 0

    for a, b in zip(s, s[::-1]):
        if a != b:
            ans += 1

    print(ans // 2)


if __name__ == '__main__':
    main()

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

Solution (Python):
S = input()
print(sum(s != t for s, t in zip(S, S[::-1])) // 2)

Solution (Python):
s = input()

if len(s) % 2 == 1:
    s_1 = s[:len(s)//2]
    s_2 = ''.join(list(reversed(s[len(s)//2+1:])))
else:
    s_1 = s[:len(s)//2]
    s_2 = ''.join(list(reversed(s[len(s)//2:])))
    
c = 0
for i in range(len(s_1)):
    if(s_1[i] != s_2[i]):
        c += 1

print(c)

Solution (Python):
import collections

S = collections.deque(input())
ans = 0

while len(S) > 1:
    if S.pop() != S.popleft():
        ans += 1

print(ans)

Solution (Python):
def main():
    s= str(input())
    n = int(len(s))
    num = 0
    for i in range(n//2):
        if s[i] != s[-i-1]:
            num += 1
    print(num)               

if __name__ == "__main__":
    main()

Solution (Python):
s=list(input())

n=len(s)
count=0
for i in range(int(n/2)):
  if s[i]!=s[n-(i+1)]:
    count+=1
print(count)

Solution (Python):
S=input()
c=0
for i in range(len(S)//2):
  if S[i]!=S[-(i+1)]:
    c+=1
print(c)

Solution (Python):
s = input()
s_len = len(s)
cnt = 0
for i in range(s_len // 2):
  if s[i] != s[s_len - i -1]:
    cnt += 1
print(cnt)

Solution (Python):
s=input()
i=0
j=len(s)-1
ans=0
while i<j:
    if s[i]!=s[j]:
        ans+=1
    i+=1
    j-=1
print(ans)

Solution (Python):
s = input()
s_each = list(s)
count = 0
c = int (len(s) / 2 )



if len(s) % 2 == 0 :
    for i in range(c) :
        if s_each[i] != s_each[-1-i]:
            count += 1

else :
    for i in range(c) :
        if s_each[i] != s_each[-1-i] :
            count += 1

print (count)

Solution (Python):
s = input()

l = len(s)

ans = 0

if l%2 == 0:
	a = s[:int(l/2)]
	b = s[int(l/2):]
	
	for i in range(len(a)):
		if a[i]==b[-1*(i+1)]:
			pass
		else:
			ans = ans + 1

else:
	a = s[:int(l//2)]
	b = s[int(l//2)+1:]
	
	for i in range(len(a)):
		if a[i]==b[-1*(i+1)]:
			pass
		else:
			ans = ans + 1

print(ans)

Solution (Python):
import math
l = list(input())
if len(l) % 2 == 1:
    l.pop(math.floor(len(l)/2))
count = 0    
for i in range(int(len(l)/2)):
    if l[i] != l[-i-1]:
        count += 1
print(count)

Solution (Python):
from sys import exit, stdin
S = list(stdin.readline().rstrip())
len_S = len(S)
if len_S % 2 != 0:
    S.pop(len_S//2)
    len_S -= 1
ans = 0
for i in range(len_S//2):
    if S[i] != S[abs(i-len_S)-1]:
        ans += 1
print(ans)

Solution (Python):
s=input()
t=s[::-1]
c=0
for x in range(len(s)):
	if s[x]!=t[x]:
		c+=1
print(c//2)

Solution (Python):
s = input()
ans = 0
for i in range(int(len(s) / 2)):
    if s[i] != s[len(s) - i - 1]:
        ans += 1

print(ans)

Solution (Python):
import math
S = list(input())
N = len(S)
K = math.floor(N/2)
S1 = S[:K]
S2 = S[:-K-1:-1]
res = 0
for s1,s2 in zip(S1,S2):
    if(s1 != s2):
        res += 1
print(res)

Solution (Python):
s = input()

cnt = 0
l = len(s)
for i in range(l//2):
    if s[i] != s[-(i+1)]:
        cnt += 1
print(cnt)

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

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

Solution (Python):

s = input()
ans = sum(s[i] != s[~i] for i in range(len(s) // 2))
print(ans)

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

Solution (Python):
s = input()
l = len(s)
s1 = s[:l//2]
s2 = s[l//2:][::-1]
c = 0
for i,j in zip(s1,s2):
  if i != j:
    c += 1
print(c)

Solution (Python):
s = input()
ans = 0
for i in range(len(s) // 2):
    ans += s[i] != s[-(i + 1)]
print(ans)

Solution (Python):
s = input()
cnt = 0

for i in range(len(s)//2):
    if s[i] != s[-i-1]:
        cnt += 1
print(cnt)

Solution (Python):
s = input()
cnt = 0
for i in range(len(s)):
  if s[i] == s[len(s)-1-i]:
    continue
  else:
    cnt += 1
print(int(cnt/2))

Solution (Python):
s = input().strip()
ans = 0

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

Solution (Python):


import sys



s= input()




total=0
for i in range(0,len(s)//2):
	if (s[i]!=s[len(s)-i-1]):
		total+=1
print(total)

Solution (Python):
a = input()
longs = int(len(a))
if(longs % 2 == 0):
    b = a[:int(longs/2)]
    c = a[int(longs/2):]
    twolongs = int(longs/2)
else:
    b = a[:int(longs/2)+1]
    c = a[int(longs/2):]
    twolongs = int(longs/2)+1

count = 0
for i in range(twolongs):
    if(b[i]==c[twolongs-i-1]):
        continue
    else:
        count +=1

print(count)

Solution (Python):
s = input()
cnt = 0
chk = int(len(s) % 2)
half = int(len(s) / 2)

if chk == 0:
    str1 = s[:half]
    str2 = s[half:]
else:
    str1 = s[:half]
    str2 = s[half+1:]

for i in range(half):
    if str1[i] != str2[half-i-1]:
        cnt += 1
print(cnt)

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

Solution (Python):
from heapq import heappush,heappop,heapify
from collections import deque,defaultdict,Counter
import itertools
from itertools import permutations,combinations
import sys
import bisect
import string
import math
import time
import random
def I():
    return int(input())
def MI():
    return map(int,input().split())
def LI():
    return [int(i) for i in input().split()]
def LI_():
    return [int(i)-1 for i in input().split()]
def StoI():
    return [ord(i)-97 for i in input()]
def ItoS(nn):
    return chr(nn+97)
def GI(V,E,Directed=False,index=0):
    org_inp=[]
    g=[[] for i in range(n)]
    for i in range(E):
        inp=LI()
        org_inp.append(inp)
        if index==0:
            inp[0]-=1
            inp[1]-=1
        if len(inp)==2:
            a,b=inp
            g[a].append(b)
            if not Directed:
                g[b].append(a)
        elif len(inp)==3:
            a,b,c=inp
            aa=(inp[0],inp[2])
            bb=(inp[1],inp[2])
            g[a].append(bb)
            if not Directed:
                g[b].append(aa)
    return g,org_inp
def show(*inp,end='\n'):
    if show_flg:
        print(*inp,end=end)
YN=['Yes','No']
mo=10**9+7
inf=float('inf')
l_alp=string.ascii_lowercase
u_alp=string.ascii_uppercase
ts=time.time()

input=lambda: sys.stdin.readline().rstrip()

def ran_input():
    import random
    n=random.randint(4,16)
    a=sorted([random.randint(0,5) for _ in range(n)])[::-1]
    return n,a

show_flg=False
show_flg=True

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

Solution (Python):

S = list(input())

ans = 0
if len(S)%2 == 0:
    mid = len(S)//2 - 1
    mid2 = mid + 1
    for i in range(len(S)//2):
        if S[mid-i] != S[mid2+i]:
            ans += 1
    print(ans)
    
else:
    mid = len(S)//2
    for i in range(len(S)//2):
        if S[mid-i-1] != S[mid+i+1]:
            ans += 1
    print(ans)

Solution (Python):
S = input()

c = 0
n = len(S)//2
SS = S[::-1]

S = S[0:n]
SS = SS[0:n]

for i in range(n):
    if S[i] == SS[i]:
        continue
    else:
        c += 1

print(c)

Solution (Python):
S=input()
num=0
for i in range(len(S)//2):
  if S[i]!=S[-(i+1)]:
    num+=1
print(num)

Solution (Python):
s=list(input())
cnt=0
i=0
j=len(s)-1
while i<j:
  if s[i]!=s[j]:
    cnt+=1
  i+=1
  j-=1
print(cnt)

Solution (Python):
def b():
  from math import ceil
  S = input()
  s1,s2 = S[:ceil(len(S) / 2)],S[len(S) // 2:][::-1]
  ans = 0
  for i in range(len(S) // 2):
    ans += int(s1[i] != s2[i])
  print(ans)
b()

Solution (Python):
s=input()
a=0
for i in range(0,len(s)//2):
    a+=(s[i] != s[len(s) - i - 1])
print(a)

Solution (Python):
S=input()
ans=0
for f,r in zip(S,reversed(S)):
  if f==r:
    continue
  else:
    ans+=1
print(ans//2)

Solution (Python):
s=input()
c=0
while len(s)>=2:
    if s[0]==s[-1]:
        s=s[1:-1]
    else:
        c+=1
        s=s[1:-1]
print(c)

Solution (Python):
S = str(input())
cont = 0

l = [str(x) for x in list(str(S))]
for i in range(int(len(l) / 2)):
    if l[i] == l[len(l) - i - 1]:
        continue
    else:
        cont += 1
print(cont)

Solution (Python):
s=input()
count = 0
for i in range(len(s)//2):
  if s[i] != s[len(s)-1-i]:
    count += 1
print(count)

Solution (Python):
s=input()
n=len(s)
res = 0
for i in range(n):
  if s[i] != s[n - i - 1]:
    res += 1
print(int(res / 2))

Solution (Python):
s = input()

lim = len(s) // 2

count = 0

for i in range(lim):
    if s[i] != s[-1*(i+1)]:
        count += 1
print(count)

Solution (Python):
from collections import Counter

s = input()

length = len(s)

x = length // 2
if length % 2:
    f, l = s[:x], s[x+1:][::-1]
else:
    f, l = s[:x], s[x:][::-1]



count = 0

for x, y in zip(f, l):
    if x != y:
        count += 1

print(count)

Solution (Python):
S = input()

l = len(S)

cnt = 0
for i in range(l // 2):
    if S[i] != S[~i]:
        cnt += 1

print(cnt)

Solution (Python):
S = list(input())
ans = 0

for i in range(len(S)//2):
    if S[i] != S[len(S)-1-i]:
        ans += 1

print(ans)

Solution (Python):
s = list(input())
a=len(s)
count = 0
for i in range(a//2):
    if s[0+i]!=s[a-1-i]:
        count+=1
print(count)

Solution (Python):
S = list(input())
ans = 0
r = len(S) - 1
for l in range(len(S)//2):
	if S[l] != S[r]:
		ans += 1
	r -= 1
print(ans)

Solution (Python):
s = input()
a = len(s)
b = int(a/2)
ans = 0
for i in range(b) :
    if s[i] != s[-i-1] :
        ans += 1
print(ans)

Solution (Python):
S = input()

res = 0
for i in range(len(S) // 2):
    if S[i] != S[len(S) - i - 1]:
        res += 1
print(res)

Solution (Python):
s = input()
count = 0
for i in range(len(s) //2):
    if s[i] != s[len(s) - 1 - i] :
        count+= 1
print(count)

Solution (Python):
s=input()

n=len(s)
cnt=0
for i in range(0,n//2):
    if s[i]==s[n-1-i]:
        continue
    else:
        cnt+=1

print(cnt)

Solution (Python):
S=input()
ans=0
for i in range(len(S)//2):
  ans+=(S[i]!=S[-1-i])
print(ans)

Solution (Python):
s=input();a=0
for i in range(len(s)//2):
  if s[i]!=s[~i]:a+=1
print(a)

Solution (Python):
s = list(input())
ans = 0
for i in range(len(s)//2):
    if s[i] != s[-(i+1)]:
        ans += 1

print(ans)

Solution (Python):
S = list(input())
R = list(reversed(S))

cnt = 0
for x,y in zip(S,R):
  if x != y:
    cnt += 1

print(cnt//2)

Solution (Python):
s = input()
cnt = 0
for i in range(len(s)//2):
    if s[i] != s[-i-1]:
        cnt +=1
print(cnt)

Solution (Python):
S = input()
l = len(S)
count = 0
for i in range(l//2):
    if S[i] != S[-i-1]:
        count += 1
    else:
        continue

print(count)

Solution (Python):
s=input()
a=0
b=s[::-1]
for i in range(len(s)//2):
  if s[i]!=b[i]:
    a+=1
print(a)

Solution (Python):
s = input()
n = len(s)
h = n//2

cnt = 0

for i in range(h):
    if s[i] != s[-(i+1)]:
        
        cnt += 1
print(cnt)

Solution (Python):
S = input()

def kaibun(string):
    count = 0
    strli = list(string)
    for i in range(len(string)//2):
        if strli[i] == strli [-i-1]:
            continue
        else:
            count += 1
    return count

print(kaibun(S))

Solution (Python):
s = input()
l, r = 0, len(s) - 1
ans = 0
while l < r:
    ans += (s[l] != s[r])
    l += 1
    r -= 1
print(ans)

Solution (Python):
s=str(input())
n=len(s)
l=list(s)
if(n%2==0):
  p=l[0:n//2]
  q=l[n//2:]
else:
  p=l[:n//2]
  q=l[(n//2+1):]
q.reverse()
cnt=0
m=[x for x in range(len(p))]
for num in m:
  if(p[num]!=q[num]):
    cnt+=1
print(cnt)

Solution (Python):
S = input()
c = 0
for n in range(len(S)//2):
    if(S[n] != S[-n-1]):
        c = c + 1
print(c)

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

Solution (Python):
s = input()
count = 0

for i in range(len(s)//2):
    if s[i]!=s[-i-1]:
        count+=1

print(count)

Solution (Python):
S = input()
n = len(S)
ans = 0
for i in range(n//2):
    if S[i] != S[n-i-1]:
        ans += 1
print(ans)

Solution (Python):
s = list(input().strip())
ans = len([x for x, y in zip(s, s[::-1]) if x != y]) // 2
print (ans)

Solution (Python):
def solve():
  s = input()
  n = len(s)
  check = n//2
  ans = 0
  for i in range(check):
    if s[i] != s[-1+i*-1]:
      ans += 1
  print(ans)
solve()

Solution (Python):
S = list(input())
count = 0

for i in range(int(len(S)/2)):
    if S.pop(0) != S.pop(-1):
        count += 1

print(count)

Solution (Python):
S = input()
l = len(S)
c = 0
for a, b in zip(S[:l//2+1], S[:l//2-1:-1]):
  if a != b:
    c += 1
print(c)