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 C++14 (GCC 5.4.1) (judge verdict: Accepted)

#include<iostream>
#include <string>
#include<stdio.h>

using namespace std;


int main() {
	int N;
	string S;

	cin >> N >> S;

	if (S.size() % 2 == 1) cout << "No" << endl;

	else {
		int n = S.size() / 2;
		int a = 0;
		for (int i = 0; i < n; i++) {
			if (S[i] == S[i + n]) {
				a++;
			}
		}
		if (a == n) cout << "Yes" << endl;
		else cout << "No" << endl;

	}


	
	}