import java.util.Scanner;
public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		String kaibun = sc.next();
		int mojisuu = kaibun.length();

		if(kaibun.substring(0,(mojisuu-1)/2).equals(kaibun.substring((mojisuu+3)/2-1,mojisuu))) {
			System.out.print("Yes");
		}
		else {
			System.out.print("No");
		}
	}
} import java.util.Scanner; Scanner java.util public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		String kaibun = sc.next();
		int mojisuu = kaibun.length();

		if(kaibun.substring(0,(mojisuu-1)/2).equals(kaibun.substring((mojisuu+3)/2-1,mojisuu))) {
			System.out.print("Yes");
		}
		else {
			System.out.print("No");
		}
	}
} Main public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		String kaibun = sc.next();
		int mojisuu = kaibun.length();

		if(kaibun.substring(0,(mojisuu-1)/2).equals(kaibun.substring((mojisuu+3)/2-1,mojisuu))) {
			System.out.print("Yes");
		}
		else {
			System.out.print("No");
		}
	} main {
		Scanner sc = new Scanner(System.in);
		String kaibun = sc.next();
		int mojisuu = kaibun.length();

		if(kaibun.substring(0,(mojisuu-1)/2).equals(kaibun.substring((mojisuu+3)/2-1,mojisuu))) {
			System.out.print("Yes");
		}
		else {
			System.out.print("No");
		}
	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) String kaibun = sc.next(); kaibun sc.next() sc.next sc int mojisuu = kaibun.length(); mojisuu kaibun.length() kaibun.length kaibun if(kaibun.substring(0,(mojisuu-1)/2).equals(kaibun.substring((mojisuu+3)/2-1,mojisuu))) {
			System.out.print("Yes");
		}
		else {
			System.out.print("No");
		} kaibun.substring(0,(mojisuu-1)/2).equals(kaibun.substring((mojisuu+3)/2-1,mojisuu)) kaibun.substring(0,(mojisuu-1)/2).equals kaibun.substring(0,(mojisuu-1)/2) kaibun.substring kaibun 0 (mojisuu-1)/2 (mojisuu-1) mojisuu 1 2 kaibun.substring((mojisuu+3)/2-1,mojisuu) kaibun.substring kaibun (mojisuu+3)/2-1 (mojisuu+3)/2 (mojisuu+3) mojisuu 3 2 1 mojisuu {
			System.out.print("Yes");
		} System.out.print("Yes") System.out.print System.out System System.out "Yes" {
			System.out.print("No");
		} System.out.print("No") System.out.print System.out System System.out "No" String[] args args public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		String kaibun = sc.next();
		int mojisuu = kaibun.length();

		if(kaibun.substring(0,(mojisuu-1)/2).equals(kaibun.substring((mojisuu+3)/2-1,mojisuu))) {
			System.out.print("Yes");
		}
		else {
			System.out.print("No");
		}
	}
} public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		String kaibun = sc.next();
		int mojisuu = kaibun.length();

		if(kaibun.substring(0,(mojisuu-1)/2).equals(kaibun.substring((mojisuu+3)/2-1,mojisuu))) {
			System.out.print("Yes");
		}
		else {
			System.out.print("No");
		}
	}
} Main
import java.util.Scanner;
public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		String kaibun = sc.next();
		int mojisuu = kaibun.length();

		if(kaibun.substring(0,(mojisuu-1)/2).equals(kaibun.substring((mojisuu+3)/2-1,mojisuu))) {
			System.out.print("Yes");
		}
		else {
			System.out.print("No");
		}
	}
}
