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 ayush
  {
  	public static void main (String[] args) throws java.lang.Exception
  	{
  	    Scanner sc = new Scanner(System.in);
  	    int t = sc.nextInt();
  	    while(t-->0)
  	    
  	    {
  	        String s = sc.next();
  	        int l =s.length();
  	        if(l%2!=0)
  	        {
  	            System.out.println("NO");
  	          
  	        }
  	     else
  	     {
  	        boolean f = false;
  	        for(int i =0;i<l/2;i++)
  	        
  	   {
  	       if(s.charAt(i)==s.charAt(i+l/2))
  	       
  	       {
  	           f = true;
  	       }
  	       else
  	       {
  	           f = false;
  	           break;
  	       }
  	   }
  	   
  	     
  	   if(f==true){
  	   System.out.println("YES");
  	    }
  	        else
  	        {
  	            System.out.println("NO");
  	        }
  	    }
  	    }
  	    
  	}
  }
  