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 9.2.1) (judge verdict: Accepted)

#include <stdio.h>
#include <string.h>


int main(){
	int n;
	if (scanf("%d", &n)==EOF){return 0;}
	if(n % 2 ==1){printf("No\n"); return 0;}
	char s[n+1];
	if (scanf("%s", s)==EOF ){return 0;}
	
	//char echo[n/2 + 1];
	//strncpy(echo, s, n/2 + 1);
	int yes = 1;
	for(int i = 0; i< n/2; i++){
		if(s[i] != s[n/2 + i]){yes = 0; break;}	
	}
	if(yes==1){printf("Yes\n");}else{printf("No\n");}
	return 0;

}