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.Scanner;
  
  public class Solution {
  
  	public static void main(String[] args) {
  		Scanner sc = new Scanner(System.in);
  		int t = sc.nextInt();
  		while (t != 0) {
  
  			String s = sc.next();
  			func(s);
  			t = t - 1;
  		}
  	}
  
  	public static void func(String s) {
  
  		if (s.length() % 2 != 0) {
  			System.out.println("NO");
  			return;
  		}
  		int i = 0;
  		int j = s.length() / 2;
  		while (j < s.length()) {
  			if (s.charAt(i) == s.charAt(j)) {
  				i++;
  				j++;
  			} else {
  				System.out.println("NO");
  				return;
  			}
  		}
  		System.out.println("YES");
  		return;
  	}
  }
  