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 { //クラス名はMain
            public static void main(String[] args) {
                //コード
              Scanner sc = new Scanner(System.in);
              int n1 = sc.nextInt();
              String wordw = sc.nextLine();
              int cut1 = n1 / 2;
              String word = sc.nextLine();
              String wordc1 = word.substring(0, cut1);
              String wordc2 = word.substring(cut1, n1);
              
              //処理打ち切り
              if (n1 <= 1) {
            System.out.println("No");
            return;
          } 
              //判定
              if (wordc1.equals(wordc2)) {
                	//等しいとき
                System.out.println("Yes");
           	}
          	else {
              		//等しくないとき
            		System.out.println("No");;
         		}
          }
        }