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.util.Scanner;
 
public class Main {
	public static void main(String[] args) {
	    Scanner sc = new Scanner(System.in);
	    int N = sc.nextInt();
	    String s = sc.next();
	    String S[] = s.split("");
	    if(N % 2 == 1) {
	        System.out.println("No");
	    }else {
	        for(int i = 0; i < N / 2; i++) {
	            if(S[i].equals(S[N / 2 + i])) {
	                if(i < N / 2 - 1) {
	                    continue;
	                }
	                System.out.println("Yes");
	            }else {
	                System.out.println("No");
	                break;
	            }
	        }
	    }
	}
}