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 java.util.*;
  
  import java.io.*;
  
  public class cf {
      static FastReader in = new FastReader();
      static final Random random = new Random();
      static long mod = 1000000007L;
      static HashMap<String, Integer> map = new HashMap<>();
  
      public static void main(String args[]) throws IOException {
  
          int n = in.nextInt();
          String[] arr = new String[n];
          for (int i = 0; i < n; i++)
              arr[i] = in.next();
          solution(n, arr);
  
      }
  
      public static void solution(int n, String[] arr) {
  
          for (String s : arr) {
              boolean ok = true;
              if ((s.length() % 2) == 0) {
                  for (int i = 0; i < s.length() / 2; i++)
                      if (s.charAt(i) != s.charAt(i + s.length() / 2))
                          ok = false;
              } else
                  ok = false;
              print(ok ? "YES" : "NO");
          }
  
      }
  
      static int max(int a, int b) {
          if (a < b)
              return b;
          return a;
      }
  
      static void ruffleSort(int[] a) {
          int n = a.length;
          for (int i = 0; i < n; i++) {
              int oi = random.nextInt(n), temp = a[oi];
              a[oi] = a[i];
              a[i] = temp;
          }
          Arrays.sort(a);
      }
  
      static <E> void print(E res) {
          System.out.println(res);
      }
  
      static int gcd(int a, int b) {
          if (b == 0) {
              return a;
          }
          return gcd(b, a % b);
      }
  
      static int lcm(int a, int b) {
          return (a / gcd(a, b)) * b;
      }
  
      static int abs(int a) {
          if (a < 0)
              return -1 * a;
          return a;
      }
  
      static class FastReader {
          BufferedReader br;
          StringTokenizer st;
  
          public FastReader() {
              br = new BufferedReader(new InputStreamReader(System.in));
          }
  
          String next() {
              while (st == null || !st.hasMoreElements()) {
                  try {
                      st = new StringTokenizer(br.readLine());
                  } catch (IOException e) {
                      e.printStackTrace();
                  }
              }
              return st.nextToken();
          }
  
          int nextInt() {
              return Integer.parseInt(next());
          }
  
          long nextLong() {
              return Long.parseLong(next());
          }
  
          double nextDouble() {
              return Double.parseDouble(next());
          }
  
          String nextLine() {
              String str = "";
              try {
                  str = br.readLine();
              } catch (IOException e) {
                  e.printStackTrace();
              }
              return str;
          }
  
          int[] readintarray(int n) {
              int res[] = new int[n];
              for (int i = 0; i < n; i++)
                  res[i] = nextInt();
              return res;
          }
  
          long[] readlongarray(int n) {
              long res[] = new long[n];
              for (int i = 0; i < n; i++)
                  res[i] = nextLong();
              return res;
          }
      }
  
  }
  