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,i,J;
char S[100];
J=0;
scanf("%d", &N);
if(N%2==0){
	for(i=0;i<=N;i++)
		scanf("%s",S);
	for(i=0;i<=N/2;i++){
		if(S[i]==S[i+N/2])
			J++;
	}
  	if(J==N/2){
		puts("Yes");
		return 0;
    }
}
puts("No");
}