import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class Main {

	public static void main(String[] args) throws IOException {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

		String S = br.readLine();
		
		int first = (S.length()-1) / 2;
		int second = (S.length()+3) / 2;
		
		String fs = S.substring(0, first);
		String ss = S.substring(second - 1, S.length());
		
		if(fs.equals(ss))
			System.out.println("Yes");
		else
			System.out.println("No");
	}

} import java.io.BufferedReader; BufferedReader java.io import java.io.IOException; IOException java.io import java.io.InputStreamReader; InputStreamReader java.io public class Main {

	public static void main(String[] args) throws IOException {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

		String S = br.readLine();
		
		int first = (S.length()-1) / 2;
		int second = (S.length()+3) / 2;
		
		String fs = S.substring(0, first);
		String ss = S.substring(second - 1, S.length());
		
		if(fs.equals(ss))
			System.out.println("Yes");
		else
			System.out.println("No");
	}

} Main public static void main(String[] args) throws IOException {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

		String S = br.readLine();
		
		int first = (S.length()-1) / 2;
		int second = (S.length()+3) / 2;
		
		String fs = S.substring(0, first);
		String ss = S.substring(second - 1, S.length());
		
		if(fs.equals(ss))
			System.out.println("Yes");
		else
			System.out.println("No");
	} main {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

		String S = br.readLine();
		
		int first = (S.length()-1) / 2;
		int second = (S.length()+3) / 2;
		
		String fs = S.substring(0, first);
		String ss = S.substring(second - 1, S.length());
		
		if(fs.equals(ss))
			System.out.println("Yes");
		else
			System.out.println("No");
	} BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); br new BufferedReader(new InputStreamReader(System.in)) String S = br.readLine(); S br.readLine() br.readLine br int first = (S.length()-1) / 2; first (S.length()-1) / 2 (S.length()-1) S.length() S.length S 1 2 int second = (S.length()+3) / 2; second (S.length()+3) / 2 (S.length()+3) S.length() S.length S 3 2 String fs = S.substring(0, first); fs S.substring(0, first) S.substring S 0 first String ss = S.substring(second - 1, S.length()); ss S.substring(second - 1, S.length()) S.substring S second - 1 second 1 S.length() S.length S if(fs.equals(ss))
			System.out.println("Yes");
		else
			System.out.println("No"); fs.equals(ss) fs.equals fs ss System.out.println("Yes") System.out.println System.out System System.out "Yes" System.out.println("No") System.out.println System.out System System.out "No" String[] args args public class Main {

	public static void main(String[] args) throws IOException {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

		String S = br.readLine();
		
		int first = (S.length()-1) / 2;
		int second = (S.length()+3) / 2;
		
		String fs = S.substring(0, first);
		String ss = S.substring(second - 1, S.length());
		
		if(fs.equals(ss))
			System.out.println("Yes");
		else
			System.out.println("No");
	}

} public class Main {

	public static void main(String[] args) throws IOException {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

		String S = br.readLine();
		
		int first = (S.length()-1) / 2;
		int second = (S.length()+3) / 2;
		
		String fs = S.substring(0, first);
		String ss = S.substring(second - 1, S.length());
		
		if(fs.equals(ss))
			System.out.println("Yes");
		else
			System.out.println("No");
	}

} Main
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class Main {

	public static void main(String[] args) throws IOException {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

		String S = br.readLine();
		
		int first = (S.length()-1) / 2;
		int second = (S.length()+3) / 2;
		
		String fs = S.substring(0, first);
		String ss = S.substring(second - 1, S.length());
		
		if(fs.equals(ss))
			System.out.println("Yes");
		else
			System.out.println("No");
	}

}