CSES - E4590 2017 1 - Palindrome quiz
  • Time limit: 1.00 s
  • Memory limit: 512 MB

Teemu likes collecting books, especially those which are palindromes. Unfortunately books are long and Teemu does not exactly fancy reading. That's why he has asked you to help to decide if the books is a palindrome and hence worth adding to his collection.

A book is a palindrome if it reads the same from front to back and back to front ignoring the case and non-letter characters.

Input

The input contains the contents of the book s on a single line. The book may contain space characters (ASCII 32) and any printable ASCII characters.

Output

Print YES if the book is a palindrome and NO if the book is not.

Limits

  • 1 \le \text{length}(s) \le 10^6

Example

Input:

No 'x' in Nixon.

Output:

YES

The input is noxinnixon when non-letter characters have been removed and letters have been converted to lower case.

Input:

This is not a palindrome

Output:

NO