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: Runtime Error)

#include<stdio.h>
#include <stdlib.h>
int main()
{
  int N,i;
  char S[N+1];
  scanf("%d",&N);
  scanf("%s",&S);
  if(N%2==0)
  {
    for(i=0;i<N/2;i++)
    {
     if(S[i]!=S[N/2+i])
     {
       printf("No");
       exit(0);
     }

    }
    printf("Yes");
  }
  else
  {
    printf("No");
  }
}