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 (GCC 5.4.1) (judge verdict: Wrong Answer)

/*  ABC145_B */
#include <stdio.h>

int main(void){
	int N = 0;
	char S[101] = "";
	scanf("%d",&N);
	scanf("%s",S);
	int i;
	int h = N/2;
	for(i=0;i<h;i++){

		if(S[i]!=S[i+h]){
			break;
		}
		if(i+1==h){
			printf("Yes");
			return 0;
		}
	}
	printf("No");
	return 0;
}