import java.util.Scanner;

public class Main {

public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    //思路：双指针或者库方法
    String s=sc.next();
    StringBuilder s2=new StringBuilder(s).reverse();
    if(s.equals(s2.toString()))System.out.println("yes");
    else System.out.println("no");
}   

}