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: # SHRi GANESHA    author: Kunal Verma #
  
  import os
  import random
  import sys
  from collections import Counter
  from heapq import heapify, heappop
  
  from itertools import *
  
  from io import BytesIO, IOBase
  from math import inf, gcd
  
  
  def lcm(a, b):
      return (a * b) // gcd(a, b)
  
  
  '''
      mod = 10 ** 9 + 7
      fac = [1]
      for i in range(1, 2 * 10 ** 5 + 1):
          fac.append((fac[-1] * i) % mod)
      fac_in = [pow(fac[-1], mod - 2, mod)]
      for i in range(2 * 10 ** 5, 0, -1):
          fac_in.append((fac_in[-1] * i) % mod)
      fac_in.reverse()
      def comb(a, b):
          if a < b:
              return 0
          return (fac[a] * fac_in[b] * fac_in[a - b]) % mod
  '''
  
  
  # MAXN = 10000004
  # spf = [0 for i in range(MAXN)]
  # adj = [[] for i in range(MAXN)]
  def sieve():
      global spf, adj, MAXN
      spf[1] = 1
      for i in range(2, MAXN):
          spf[i] = i
  
      for i in range(2, MAXN):
          if i * i > MAXN:
              break
          if (spf[i] == i):
              for j in range(i * i, MAXN, i):
                  if (spf[j] == j):
                      spf[j] = i
  
  
  def getdistinctFactorization(n):
      global adj, spf, MAXN
      for i in range(1, n + 1):
          index = 1
          x = i
          if (x != 1):
              adj[i].append(spf[x])
          x = x // spf[x]
          while (x != 1):
              if (adj[i][index - 1] != spf[x]):
                  adj[i].append(spf[x])
                  index += 1
              x = x // spf[x]
  
  
  def printDivisors(n):
      i = 2
      z = [1, n]
      while i <= sqrt(n):
          if (n % i == 0):
              if (n / i == i):
                  z.append(i)
              else:
                  z.append(i)
                  z.append(n // i)
          i = i + 1
      return z
  
  
  def create(n, x, f):
      pq = len(bin(n)[2:])
      if f == 0:
          tt = min
      else:
          tt = max
      dp = [[inf] * n for _ in range(pq)]
      dp[0] = x
      for i in range(1, pq):
          for j in range(n - (1 << i) + 1):
              dp[i][j] = tt(dp[i - 1][j], dp[i - 1][j + (1 << (i - 1))])
      return dp
  
  
  def enquiry(l, r, dp, f):
      if l > r:
          return inf if not f else -inf
      if f == 1:
          tt = max
      else:
          tt = min
      pq1 = len(bin(r - l + 1)[2:]) - 1
      return tt(dp[pq1][l], dp[pq1][r - (1 << pq1) + 1])
  
  
  def SieveOfEratosthenes(n):
      prime = [True for i in range(n + 1)]
      p = 2
      while (p * p <= n):
          if (prime[p] == True):
              for i in range(p * p, n + 1, p):
                  prime[i] = False
          p += 1
      x = []
      for i in range(2, n + 1):
          if prime[i]:
              x.append(i)
      return x
  
  
  def main():
  
  
  
  
      for _ in range(int(input())):
          s=list(input().strip())
          n=len(s)
          if n%2:
              print("NO")
          else:
              if s[:n//2]+s[:n//2]==s:
                  print("YES")
              else:
                  print("NO")
  
  
  
  # Fast IO Region
  BUFSIZE = 8192
  
  
  class FastIO(IOBase):
      newlines = 0
  
      def __init__(self, file):
          self._fd = file.fileno()
          self.buffer = BytesIO()
          self.writable = "x" in file.mode or "r" not in file.mode
          self.write = self.buffer.write if self.writable else None
  
      def read(self):
          while True:
              b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE))
              if not b:
                  break
              ptr = self.buffer.tell()
              self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr)
          self.newlines = 0
          return self.buffer.read()
  
      def readline(self):
          while self.newlines == 0:
              b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE))
              self.newlines = b.count(b"\n") + (not b)
              ptr = self.buffer.tell()
              self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr)
          self.newlines -= 1
          return self.buffer.readline()
  
      def flush(self):
          if self.writable:
              os.write(self._fd, self.buffer.getvalue())
              self.buffer.truncate(0), self.buffer.seek(0)
  
  
  class IOWrapper(IOBase):
      def __init__(self, file):
          self.buffer = FastIO(file)
          self.flush = self.buffer.flush
          self.writable = self.buffer.writable
          self.write = lambda s: self.buffer.write(s.encode("ascii"))
          self.read = lambda: self.buffer.read().decode("ascii")
          self.readline = lambda: self.buffer.readline().decode("ascii")
  
  
  sys.stdin, sys.stdout = IOWrapper(sys.stdin), IOWrapper(sys.stdout)
  input = lambda: sys.stdin.readline().rstrip("\r\n")
  
  if __name__ == '__main__':
      main()