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: # '''
  #      |\_/|                  
  #      | @ @   Woof! 
  #      |   <>              _  
  #      |  _/\------____ ((| |))
  #      |               `--' |   
  #  ____|_       ___|   |___.' 
  # /_/_____/____/_______|
  # I am here to guard this code, woof!
  # '''
  
  
  
  import sys
  from sys import stdin, stdout
  from math import ceil, floor, sqrt, log, log2, log10
  from collections import Counter
   
  int_max = float('inf')
  int_min = -(float('inf'))
  mod = 10**9 + 7
  ANS = []
  # infile = open(sys.argv[1], "r")
  # input = infile.readline
  input = stdin.readline
   
  def solve():
      pass
   
  t = int(input())
  # t = 1
   
  for i in range(t):
      # n = int(input())
      # n, k = map(int, input().split())
      # arr =  list(map(int, input().split()))
      # arr = list(input())
      s = input().strip()
  
      n = len(s)
      if n%2 == 1:
          print("NO")
          continue
      if s[:n//2] == s[n//2: n]:
          print("YES")
      else:
          print('NO')
  
  # print('\n'.join(ANS))