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 Python (3.4.3) (judge verdict: Accepted)

# 初期入力
S = input()

# Sを前半ー中心ー後半に分ける
S_mae = ""
S_mae_gyaku = ""
S_usiro =""
S_usiro_gyaku =""
S_tyusin_num =0
if len(S) % 2 ==1:
    S_tyusin_num =(len(S) )//2
    S_mae =S[:S_tyusin_num]
    S_mae_gyaku = S_mae[::-1]
    S_usiro = S[(-1)*S_tyusin_num:]
    S_usiro_gyaku = S_usiro[::-1]
    if S_mae == S_mae_gyaku and S_usiro == S_usiro_gyaku and S_mae == S_usiro: 
        print("Yes") # 前半だけで回文→S_mae == S_mae_gyaku
    else:
        print("No")