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: Wrong Answer)

#include<stdio.h>

int main(){
int length;
char moziretu[101];
int hantei=0;
int i=0;
	fflush(0);
	scanf("%d",&length);
	fflush(0);
	scanf("%s",moziretu);
	length=length/2;

	while(i<length){
		if(moziretu[i]!=moziretu[i+length]){
			hantei=1;
			break;
		}else{
			i++;
		}
	}

	if(hantei==0){
		printf("Yes");

	}else{
		printf("No");
	}

}