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: Accepted)

#include<stdio.h>
int main(void)
{
	int n,i;
	char s[101];
	scanf("%d %s", &n, s);
	if(n%2==1)
	printf("No\n");
	else
	{
		for(i=0; i<n/2; i++)
		{
			if(s[i]!=s[i+n/2])
			{
				printf("No\n");
				break;
			}
			if(i==n/2-1)
			printf("Yes\n");
		}
	}
	
	return 0;
}