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(){
	int n;scanf(" %d",&n);
  	char che[n+1];
 	scanf(" %s",che);
  	if(n&1){puts("No");return 0;}
  	int ye = 1;
  	for(int i = 0,j = (n>>1); j < n && ye;++i,++j){
    	if(che[i] != che[j]) ye = 0;
    }
  	if(ye) puts("Yes");
  	else puts("No");
  	return 0; 
}