Four-digit palindrom#8618

Four-digit palindrom

1 second
128 megabytes
Very easy

A four-digit natural number is given. Determine whether it is a palindrome. A natural number is a palindrome if it reads the same from left to right and from right to left. For example, the number is a palindrome.

Input

One four-digit natural number .

Output

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

Examples

Example 1

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Example 2

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