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,f=0,j=0;;
	char a[100],b[100];
	scanf("%d%s",&n,a);
	for(i=n/2;i<n;i++){
		b[j]=a[i];
		j++;
	}
	for(i=0;i<n/2;i++){
		if(a[i]!=b[i]){
			f=1;
		}
	}
	if(f==1||n%2==1){
		printf("No\n");
	}
	else{
		printf("Yes\n");
	}
	return 0;
}