description: A string is called square if it is some string written twice in a row. For example, the strings "aa", "abcabc", "abab" and "baabaa" are square. But the strings "aaa", "abaaab" and "abcdabc" are not square.
  
  For a given string s determine if it is square.
  
  Input
  
  The first line of input data contains an integer t (1 ≤ t ≤ 100) —the number of test cases.
  
  This is followed by t lines, each containing a description of one test case. The given strings consist only of lowercase Latin letters and have lengths between 1 and 100 inclusive.
  
  Output
  
  For each test case, output on a separate line:
  
    * YES if the string in the corresponding test case is square, 
    * NO otherwise. 
  
  
  
  You can output YES and NO in any case (for example, strings yEs, yes, Yes and YES will be recognized as a positive response).
  
  Example
  
  Input
  
  
  10
  a
  aa
  aaa
  aaaa
  abab
  abcabc
  abacaba
  xxyy
  xyyx
  xyxy
  
  
  Output
  
  
  NO
  YES
  NO
  YES
  YES
  YES
  NO
  NO
  NO
  YES
solution: 
  
  
  import java.math.*;
  import java.net.Inet4Address;
  import  java.util.*;
  public class sampleEditor_codeforces {
      static   int  mod=1000000007;
      static  int mod2=1000003;
      static  Scanner sc = new Scanner(System.in);
  
      static class Pair implements Comparable<Pair>{
          int x;
          int y;
  
          public Pair(int px , int py){
              x = px;
              y = py;
          }
  
          @Override
          public int compareTo(Pair pair){
              if (x > pair.x)
                  return 1;
              else if (x == pair.x)
                  return 0;
              else
                  return -1;
          }
  
      }
  
  
      public static void loop(int [] a,int l,int r){
          for(int i=l;i<r;i++){
              a[i]=sc.nextInt();
          }
      }
      public static long binaryToDecimal(String binary){
          int n=binary.length();
          int i=n-1;
          long sum=0;
          long two=1;
          while(i>=0){
              sum+=two*(binary.charAt(i)-'0')%mod2;
              two*=2;
              i--;
          }
          return sum;
      }
  
  
      public static boolean isSorted(int[] arr) {
          int n = arr.length;
          for (int i = 0; i < n - 1; i++) {
              if (arr[i] > arr[i + 1]) {
                  return false;
              }
          }
  
          return true;
      }
  
      public static void reverse(int[] arr) {
          int l = 0;
          int r = arr.length - 1;
          while (l < r) {
              int temp = arr[l];
              arr[l] = arr[r];
              arr[r] = temp;
              l++;
              r--;
          }
      }
  
      public static void reverse(int[] arr,int l,int r) {
  
          while (l < r) {
              int temp = arr[l];
              arr[l] = arr[r];
              arr[r] = temp;
              l++;
              r--;
          }
      }
      public  static  boolean isPalindrome(int n,int [] a,int x1){
          int [] b=new int[n];
          int m=0;
          for(int i=0;i<n;i++){
              if(a[i]!=x1){
                  b[m++]=a[i];
              }
          }
          for(int i=0;i<m;i++){
              if(b[i]!=b[m-1-i]){
                  return false;
              }
          }
          return true;
  
  
      }
  
      public static void solve(String s) {
          int n=s.length();
          if(n%2!=0) System.out.println("NO");
          else{
              int i=0;
              int mid=n/2;
              int j=mid;
              while(i<mid && j<n){
                  if(s.charAt(i)!=s.charAt(j)){
                      System.out.println("NO");
                      return;
                  }
                  i++;j++;
              }
              System.out.println("YES");
          }
      }
  
  
      public static void main(String args[]) {
  //        Scanner sc = new Scanner(System.in);
          int t = sc.nextInt();
          while (t-- > 0) {
              String s=sc.next();
  
              solve(s);
          }
      }
  
  
  }