Problem Statement

Given is a string S consisting of lowercase English letters.
Determine whether adding some number of a's (possibly zero) at the beginning of S can make it a palindrome.
Here, a string of length $N, A=A_1A_2\ldots A_N$, is said to be a palindrome when A_i=A_{N+1-i} for every $1\leq i\leq N$.

Input

Input is given from Standard Input in the following format:
S

Output

If adding some number of a's (possibly zero) at the beginning of S can make it a palindrome, print Yes; otherwise, print No.

Constraints

• $1 \leq \lvert S \rvert \leq 10^6$
• S consists of lowercase English letters.

Sample Input 1

kasaka

Sample Output 1

Yes

By adding one a at the beginning of kasaka, we have akasaka, which is a palindrome, so Yes should be printed.

Sample Input 2

atcoder

Sample Output 2

No

Adding any number of a's at the beginning of atcoder does not make it a palindrome.

Sample Input 3

php

Sample Output 3

Yes

php itself is a palindrome. Adding zero a's at the beginning of S is allowed, so Yes should be printed.

见题面 Input 部分

见题面 Output 部分