Problem:
Score : 200 points

Problem Statement

A string S of an odd length is said to be a strong palindrome if and only if all of the following conditions are satisfied:

S is a palindrome.

Let N be the length of S. The string formed by the 1-st through ((N-1)/2)-th characters of S is a palindrome.

The string consisting of the (N+3)/2-st through N-th characters of S is a palindrome.

Determine whether S is a strong palindrome.

Constraints

S consists of lowercase English letters.

The length of S is an odd number between 3 and 99 (inclusive).

Input

Input is given from Standard Input in the following format:

S

Output

If S is a strong palindrome, print Yes;
otherwise, print No.

Sample Input 1

akasaka

Sample Output 1

Yes

S is akasaka.

The string formed by the 1-st through the 3-rd characters is aka.

The string formed by the 5-th through the 7-th characters is aka.
All of these are palindromes, so S is a strong palindrome.

Sample Input 2

level

Sample Output 2

No

Sample Input 3

atcoder

Sample Output 3

No

Solution in C++14 (GCC 5.4.1) (judge verdict: Wrong Answer)

#include <bits/stdc++.h>
using namespace std;

int main(){
string txt;
 cin >> txt;
 int N = txt.length();
  int n = (N-1)/2;
  int m = (N+3)/2-1;
  int i;
  char c;
  char d;
  int t=0;
  for(i=0;i<n;i++){
   c = txt[i];
   d = txt[n-i-1];
   if(c!=d)t++;}
  for(i=m;i<N;i++){
   c = txt[i];
   d = txt[N-1-i+m];
   if(c!=d)t++;}
  if(t>0)cout << "No" << endl; 
  else{cout << "Yes" << endl;} 
  return 0;
}