// 2019 IUSB Programming Competition
// Round 1 Problem 2
// Check if a string is a palindrome
// Solution by Liguo Yu

import java.util.ArrayList;
import java.util.Scanner;

public class round1_p2
{
	public static void main(String[] main)
	{
		Boolean yes = true;
		Scanner scan = new Scanner(System.in);
		String input = scan.nextLine();
		
		input = input.toLowerCase();
		
		ArrayList<Character> filtered = new ArrayList<>();
		
		for (int i = 0; i < input.length(); i++)
		{
			if (input.charAt(i) >= 'a' && input.charAt(i) <= 'z' )
			{
				filtered.add(input.charAt(i));
			}
		}
		
		for (int i = filtered.size() - 1; i >= 0; i--)
		{
			if (filtered.get(i) != filtered.get(filtered.size() - i - 1))
			{
				yes = false;
			}
		}
		
		if(yes == true)  System.out.println("yes");
		else System.out.println("no");
		
		return;
	}
}