Problem Statement
Given is a string SS consisting of lowercase English letters. Determine whether adding some number of a's (possibly zero) at the beginning of SS can make it a palindrome.
Here, a string of length NN, A=A_1A_2\ldots A_NA=A1A2…AN, is said to be a palindrome when A_i=A_{N+1-i}Ai=AN+1−i for every 1\leq i\leq N1≤i≤N.
Constraints
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1 \leq \lvert S \rvert \leq 10^61≤∣S∣≤106
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SS consists of lowercase English letters.
Input
Input is given from Standard Input in the following format:
SS
Output
If adding some number of a's (possibly zero) at the beginning of SS can make it a palindrome, print Yes; otherwise, print No.