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 sys
  import os.path
  from collections import *
  import math
  import bisect
  import heapq as hq
  from fractions import Fraction
  from random import randint
  
  if os.path.exists("input.txt"):
      sys.stdin = open("input.txt", "r")
      sys.stdout = open("output.txt", "w")
  
  input = sys.stdin.readline
  
  ##########################################################
  def solve():
      s = input().strip('\n')
      if len(s) % 2:
          print("NO")
          return
      n = len(s)
      if(s[:n // 2] == s[n //2 :]):
          print("YES")
      else:
          print("NO")
      
  t = int(input())
  while t:
      t -= 1
      solve()
  
  
  ##########################################################
  