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: Runtime Error)

#include<stdio.h>
#include<string.h>
int main()
{
	int len, i;
	char s[100], a[50], b[50];
	scanf("%d", len);
	for (i = 0; i < len; i++)
		scanf("%c", &s[i]);

	if (len % 2 == 0)
	{
		for (i = 0; i < len / 2; i++)
		{
			a[i] = b[i];
		}

		for (i = 0; i < len / 2; i++)
		{
			b[i] = s[len / 2 + i];
		}

		if (strcmp(a, b) == 0)
			printf("Yes");
		else
			printf("No");
	}

	else
		printf("No");

	return 0;
}