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 math
  T=int(input())
  for t in range(T):
    #n=int(input())
    #x,y=map(int,input().split())
    #lst=list(map(int,input().split()))
    s=input()
    #dct=dict()
    #for i in lst:
      #dct[i]=0
    #for i in lst:
      #dct[i]+=1
    # start your code from here
    if len(s)%2!=0:
        print('NO')
        continue
    if s[:len(s)//2]==s[len(s)//2:]:
        print('YES')
    else:
        print('NO')