Palindrome Checker

Your task is to determine whether a given string is a palindrome. A palindrome is a string that reads the same backwards as forwards. For example, the string "madam" is a palindrome while "hello" is not.

Check the input string and output YES if it is a palindrome, or NO if it is not.

The mathematical condition for a string s of length n to be a palindrome can be expressed in latex as: $$\forall i \; (1 \leq i \leq n),\; s[i] = s[n-i+1]$$.

inputFormat

The input consists of a single line containing a non-empty string. The string may include letters, numbers, and symbols.

Input is read from standard input (stdin).

outputFormat

Output a single line containing the string "YES" if the input is a palindrome, or "NO" otherwise. The output should be written to standard output (stdout).

madam

YES