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.*;

public class Main {
	public static void main (String[] args){
		Scanner sc = new Scanner(System.in);
		int N = sc.nextInt();
		String S = sc.next();
		char[] s = S.toCharArray();
		boolean A = true;
		if(N%2 != 0) {
			A = false;
		}
		for(int i = 0; i < N/2; i++) {
			if(s[i] != s[(N/2)+i]) {
				A = false;
				break;
			}
		}
		if(A == true) {
			System.out.println("Yes");
		}
		else {
			System.out.println("No");
		}
	}
}