import java.util.Scanner;
import java.lang.String;

public class Main {

	public static void main(String[] args) {
		Scanner input = new Scanner(System.in);
		String S = input.nextLine();
		String S1 = "";
		int len = S.length(), i, j;
		
		for(i = 0; i < len; i++)
		{
			S1 = S.charAt(i) + S1;
		}
		
		if(S.equals(S1))
		    System.out.print("Yes");
		else
			System.out.print("No");
			
		input.close();
	}

}

法2：
import java.util.*; 
public class Main{
	
	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
	    String S = scan.next();
	    StringBuffer sb = new StringBuffer(S);
	    //String s1 = sb.reverse().toString();
	    //System.out.println(s1);
	    String s = new String(sb.reverse().toString());
	    if(s.equals(S))
	    	System.out.println("Yes");
	    else
	    	System.out.println("No");
	    
	    scan.close();
	}
}