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 static java.lang.Integer.parseInt;
  import static java.lang.Long.parseLong;
  import static java.lang.System.exit;
  import static java.lang.Math.sqrt;
  import static java.lang.Math.cbrt;
  
  import java.io.BufferedReader;
  import java.io.IOException;
  import java.io.InputStreamReader;
  import java.io.PrintWriter;
  import java.util.StringTokenizer;
  
  public class Template {
  
  	static void solve() throws Exception {
  		String str = scanString();
  		int n = str.length();
  		out.println(str.substring(0, n / 2).equals(str.substring(n / 2, n)) ? "Yes" : "No");
  	}
  
  	static int scanInt() throws IOException {
  		return parseInt(scanString());
  	}
  
  	static long scanLong() throws IOException {
  		return parseLong(scanString());
  	}
  
  	static String scanString() throws IOException {
  		while (tok == null || !tok.hasMoreTokens()) {
  			tok = new StringTokenizer(in.readLine());
  		}
  		return tok.nextToken();
  	}
  
  	static BufferedReader in;
  	static PrintWriter out;
  	static StringTokenizer tok;
  
  	public static void main(String[] args) {
  		try {
  			in = new BufferedReader(new InputStreamReader(System.in));
  			out = new PrintWriter(System.out);
  			int ttc = scanInt();
  			for (int tc = 0; tc < ttc; tc++) {
  				solve();
  			}
  			in.close();
  			out.close();
  		} catch (Throwable e) {
  			e.printStackTrace();
  			exit(1);
  		}
  	}
  }