import java.util.Scanner;

public class Solver {

 public static void main(String[] args) {
	 Scanner cin = new Scanner(System.in);

	 while(cin.hasNext()){
		 String inString = cin.nextLine();

		 if(isPalindrom(inString)){
			 System.out.println("yes");
		 }
		 else{
			 System.out.println("no");
		 }
	 }
 	}

public static boolean isPalindrom(String inString){
	StringBuilder reverseBuilder = new StringBuilder(inString).reverse(); //參考自
	String reverseInString = reverseBuilder.toString();
	return inString.equals(reverseInString);
 	}
}