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: from __future__ import division, print_function
  
  import os
  import sys
  from io import BytesIO, IOBase
  
  if sys.version_info[0] < 3:
      from __builtin__ import xrange as range
      from future_builtins import ascii, filter, hex, map, oct, zip
  
  
  class LazySegmentTree:
      def __init__(self, data, default=0, func=max):
          """initialize the lazy segment tree with data"""
          self._default = default
          self._func = func
  
          self._len = len(data)
          self._size = _size = 1 << (self._len - 1).bit_length()
          self._lazy = [pow(2,30)-1] * (2 * _size)
  
          self.data = [default] * (2 * _size)
          self.data[_size:_size + self._len] = data
          for i in reversed(range(_size)):
              self.data[i] = func(self.data[i + i], self.data[i + i + 1])
  
      def __len__(self):
          return self._len
  
      def _push(self, idx):
          """push query on idx to its children"""
          # Let the children know of the queries
          q, self._lazy[idx] = self._lazy[idx], pow(2,30)-1
  
          self._lazy[2 * idx] &= q
          self._lazy[2 * idx + 1] &= q
          self.data[2 * idx] &= q
          self.data[2 * idx + 1] &= q
  
      def _update(self, idx):
          """updates the node idx to know of all queries applied to it via its ancestors"""
          for i in reversed(range(1, idx.bit_length())):
              self._push(idx >> i)
  
      def _build(self, idx):
          """make the changes to idx be known to its ancestors"""
          idx >>= 1
          while idx:
              self.data[idx] = self._func(self.data[2 * idx], self.data[2 * idx + 1]) & self._lazy[idx]
              idx >>= 1
  
      def add(self, start, stop, value):
          """lazily add value to [start, stop)"""
          start = start_copy = start + self._size
          stop = stop_copy = stop + self._size
          while start < stop:
              if start & 1:
                  self._lazy[start] &= value
                  self.data[start] &= value
                  start += 1
              if stop & 1:
                  stop -= 1
                  self._lazy[stop] &= value
                  self.data[stop] &= value
              start >>= 1
              stop >>= 1
  
          # Tell all nodes above of the updated area of the updates
          self._build(start_copy)
          self._build(stop_copy - 1)
  
      def query(self, start, stop, default=0):
          """func of data[start, stop)"""
          start += self._size
          stop += self._size
  
          # Apply all the lazily stored queries
          self._update(start)
          self._update(stop - 1)
  
          res = default
          while start < stop:
              if start & 1:
                  res = self._func(res, self.data[start])
                  start += 1
              if stop & 1:
                  stop -= 1
                  res = self._func(res, self.data[stop])
              start >>= 1
              stop >>= 1
          return res
  
      def __repr__(self):
          return "LazySegmentTree({0})".format(self.data)
  default=pow(2,30)-1
  mod=10**9+7
  def xorSum(arr, n):
      bits = 0
      for i in range(n):
          bits |= arr[i]
      ans = (bits * pow(2, n-1,mod))%mod
      return ans
  from math import sqrt,ceil
  def find(a,i,j):
      if(i==0 and j==len(a)-1):
          return float("Inf")
      n=len(a)
      if((n-(j-i+1))//2<i):
          return a[(n-(j-i+1))//2]
      else:
          return a[j+(n-(j-i+1))//2-i+1]
  def chk(i,j,a):
      bichwale=j-i-1
  
  def main():
      for _ in range(int(input())):
          s=list(input())
          n=len(s)
          if(s[:n//2]==s[n//2:]):
              print("YES")
          else:
            print("NO")
  
              
              
                  
  
  
              
  
      
  
  
  # region fastio
  
  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")
  
  
  def print(*args, **kwargs):
      """Prints the values to a stream, or to sys.stdout by default."""
      sep, file = kwargs.pop("sep", " "), kwargs.pop("file", sys.stdout)
      at_start = True
      for x in args:
          if not at_start:
              file.write(sep)
          file.write(str(x))
          at_start = False
      file.write(kwargs.pop("end", "\n"))
      if kwargs.pop("flush", False):
          file.flush()
  
  
  if sys.version_info[0] < 3:
      sys.stdin, sys.stdout = FastIO(sys.stdin), FastIO(sys.stdout)
  else:
      sys.stdin, sys.stdout = IOWrapper(sys.stdin), IOWrapper(sys.stdout)
  
  input = lambda: sys.stdin.readline().rstrip("\r\n")
  
  # endregion
  
  if __name__ == "__main__":
      main()
  