import java.util.*;
import java.lang.*;
import java.io.*;
class Main {
static boolean isPalindrome(String s)
{
/* Two pointers initialised to 0 and 's.length()-1'.*/
int i = 0, j = s.length() - 1;
/* Looping through the string */
while (i < j) {
/* Even if one character is not equal, we will return false. */
if (s.charAt(i) != s.charAt(j))
return false;
/* Value of pointers is changed */
i++;
j--;
}
/* This means all characters are same and thus string is a palindrome*/
return true;
}
public static void main(String[] args)
{
String s = "abba";
/* First, We'll convert it to lower case. */
s = s.toLowerCase();
if (isPalindrome(s))
System.out.print("Yes");
else
System.out.print("No");
}
}