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: /* package codechef; // don't place package name! */
   
  import java.util.*;
  import java.lang.*;
  import java.io.*;
   
  /* Name of the class has to be "Main" only if the class is public. */
  public class Codechef
  {
      
      static class FastReader {
          BufferedReader br;
          StringTokenizer st;
   
          public FastReader()
          {
              br = new BufferedReader(
                  new InputStreamReader(System.in));
          }
   
          String next()
          {
              while (st == null || !st.hasMoreElements()) {
                  try {
                      st = new StringTokenizer(br.readLine());
                  }
                  catch (IOException e) {
                      e.printStackTrace();
                  }
              }
              return st.nextToken();
          }
   
          int nextInt() { return Integer.parseInt(next()); }
   
          long nextLong() { return Long.parseLong(next()); }
   
          double nextDouble()
          {
              return Double.parseDouble(next());
          }
   
          String nextLine()
          {
              String str = "";
              try {
                  str = br.readLine();
              }
              catch (IOException e) {
                  e.printStackTrace();
              }
              return str;
          }
      }
      
      static class OutputWriter {
          private final PrintWriter writer;
   
          public OutputWriter(OutputStream outputStream) {
              writer = new PrintWriter(new BufferedWriter(new OutputStreamWriter(outputStream)));
          }
   
          public OutputWriter(Writer writer) {
              this.writer = new PrintWriter(writer);
          }
   
          public void print(int[] array) {
              for (int i = 0; i < array.length; i++) {
                  if (i != 0) {
                      writer.print(' ');
                  }
                  writer.print(array[i]);
              }
          }
   
          public void printLine(int[] array) {
              print(array);
              writer.println();
          }
   
          public void close() {
              writer.close();
          }
   
          public void printLine(long i) {
              writer.println(i);
          }
   
          public void printLine(int i) {
              writer.println(i);
          }
          public void printLine(char c)
          {
              writer.println(c);
          }
   
          public void print(Object... objects) {
              for (int i = 0; i < objects.length; i++) {
                  if (i != 0) {
                      writer.print(' ');
                  }
                  writer.print(objects[i]);
              }
          }
   
          public void printLine(Object... objects) {
              print(objects);
              writer.println();
          }
      }
      
  	public static void main (String[] args) throws java.lang.Exception
  	{
  		// your code goes here
  		
  		FastReader sc = new FastReader();
  		OutputWriter out = new OutputWriter(System.out);
  		int t = sc.nextInt();
  		while(t-->0){
  		    String s = sc.next();
  		    int n = s.length();
  		    boolean ans = false;
  		    if(n%2==0){
  		        if(s.substring(0,n/2).equals(s.substring(n/2))) ans = true;
  		    }
  		  //  else{
  		  //      if(s.substring(0,n/2).equals(s.substring(n/2+1))) ans = true;
  		  //      else if(s.substring(0,n/2).equals(s.substring(n/2,n-1))) ans = true;
  		  //      else if(s.substring(1,n/2+1).equals(s.substring(n/2+1))) ans = true;
  		  //  }
  		  //  if(n==1) ans = false;
  		    out.printLine(ans?"YES":"NO");
  	    }
  		out.close();
  	}
  }