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.util.*;
  import java.lang.*;
  import java.io.*;
  
  public class Solution {
      public static void main(String args [])
      {
          Scanner obj = new Scanner(System.in);
          int t = obj.nextInt();
          obj.nextLine();
          String arr[] = new String[t];
          int count=0;
          while(t>0)
          {
              String temp = obj.nextLine();
              arr[count++]=temp;
              
      
  
              t--;
          }
  
          for(int j=0;j<arr.length;j++)
          {
              String temp = arr[j];
              if(temp.length()%2!=0)
              System.out.println("NO");
              else
              {
                  int ti =temp.length()/2-1;
                  int flag=0;
                  for(int i=0;i<=ti;i++)
                  {
                      
                      if(temp.charAt(i)==temp.charAt(i+temp.length()/2))
                      continue;
                      else
                      {
                          System.out.println("NO");
                           flag=1;
                          break;
                      }
                  }
                  if(flag==0)
                  System.out.println("YES");
              }
          }
      }}