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 (GCC 5.4.1) (judge verdict: Accepted)

#include<stdio.h>
#include<math.h>
#include<stdlib.h>
#include<string.h>
#define max(x,y)(x>y?x:y)
#define min(x,y)(x>y?y:x)
#define MOD (int)1e9+7
int dx4[]={1,0,-1,0};
int dy4[]={0,-1,0,1};
typedef long long int ll;
typedef unsigned long long int ull;
ll gcd(ll x,ll y){if(!y)return x;return gcd(y,x%y);}
ll lcm(ll x,ll y){return x/gcd(x,y)*y;}
void swap(ll *x,ll *y){ll tmp=*x;*x=*y;*y=tmp;}
int asc_cmp(const void* X,const void* Y){ll x=*(int*)X,y=*(int*)Y;if(x<y)return -1;else if(x==y)return 0;else return 1;}
int desc_cmp(const void* X,const void* Y){ll x=*(int*)X,y=*(int*)Y;if(x<y)return 1;else if(x==y)return 0;else return -1;}
typedef struct pair_{
    int x;
    int y;
}pair_t;

int main(){
    char s[200];scanf("%s",s);
    for(int i=0;i<strlen(s)/2;i++){
        if(s[i]!=s[strlen(s)-1-i]){
            printf("No\n");
            return 0;
        }
    }
    for(int i=0;i<(strlen(s)-1)/4;i++){
        if(s[i]!=s[(strlen(s)-1)/2-1-i]){
            printf("No\n");
            return 0;
        }
    }
    for(int i=(strlen(s)+3)/2-1;i<(strlen(s)-1);i++){
        if(s[i]!=s[(strlen(s)-1)-i]){
            printf("No\n");
            return 0;
        }
    }
    printf("Yes\n");
}