e-olymp
Competitions

Programming Principles 1. Week 2. September 9 - 15. PART 2

Four-digit palindrom

Four-digit number is given. Determine is it a palindrome. A positive integer is a palindrome if it is read the same from left to right and from right to left. For example the number 2332 is palindrome.

Input

Onr four-digit number n.

Output

Print "YES", if the number n is a palindrome, and "NO" otherwise.

Time limit 1 second
Memory limit 128 MiB
Input example #1
2332
Output example #1
YES
Input example #2
5446
Output example #2
NO