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 (Clang 3.8.0) (judge verdict: Accepted)

#include <stdio.h>
#include <stdlib.h>
 
 
int main(void) {
 
 
	int n,a,i,s;
	char b[100];
 
	scanf("%d",&n);
	scanf("%s",b);
 
	a = n/2;
 
	s = a;
	i=0;
	while(b[i]==b[s]&&i<a){
		i++;
		s++;
	}
 
	if(n%2 !=0 ){
		i++;
	}
	if(i == a){
		printf("Yes");
	}else{
		printf("No");
	}
 
 
	return 0;
}