Problem:
Score : 200 points

Problem Statement

Given are a positive integer N and a string S of length N consisting of lowercase English letters.

Determine whether the string is a concatenation of two copies of some string.
That is, determine whether there is a string T such that S = T + T.

Constraints

1 \leq N \leq 100

S consists of lowercase English letters.

|S| = N

Input

Input is given from Standard Input in the following format:

N
S

Output

If S is a concatenation of two copies of some string, print Yes; otherwise, print No.

Sample Input 1

6
abcabc

Sample Output 1

Yes

Let T = abc, and S = T + T.

Sample Input 2

6
abcadc

Sample Output 2

No

Sample Input 3

1
z

Sample Output 3

No

Solution in Java8 (OpenJDK 1.8.0) (judge verdict: Accepted)

import java.io.*;
 
class Main {
	public static void main(String[] args) {
		BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
		try{
			String line = reader.readLine();
			int n = Integer.parseInt(line);
			line = reader.readLine();
			char[] s =line.toCharArray();
			String ans = "Yes";
 
			if(n%2 != 0){
				ans = "No";
			}else{
				if(!(line.substring(0, n/2).equals(line.substring(n/2, n)))){
					ans = "No";
				}
			}
			System.out.println(ans);
		} catch(IOException e) {
			System.out.println(e);
		} catch(NumberFormatException e) {
			System.out.println(e);
		}
	}
}