import java.util.Scanner;
class Main{
 public static void main(String args[]){
   Scanner sc = new Scanner(System.in);
   String s = sc.next();
   int n = s.length();
   String x , y;
   x = s.substring(0,n/2);
   y = s.substring(n/2+1,n);
   if(x.equals(y)){
     System.out.println("Yes");
   }else{
     System.out.println("No");
   }
 
 }
}
/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz