import java.util.Scanner;
public class A1254 {
	public static void main(String args[]) {
		int i,k=1;
		String s;
		Scanner in  = new Scanner(System.in);
		s = in.nextLine();
		int len = s.length();//獲取字串的長度
		for(i=0;i<len/2.0;i++) {
			char st = s.charAt(i);//取字串第一個字元
			char ss = s.charAt(len-i-1);//取字串最後一個個字元
			if(ss!=st)
			{
				k=0;
				break;
			}
		}
		if(k==0)
			System.out.println("no");
		else
			System.out.println("yes");
		in.close();
	}
}