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 = 0, simnao = 0;

  scanf("%d", &n);

  char b[n+1];

  scanf("%s", b);

  if (n % 2 == 0) {

  for (int i = 0; i < n/2; i++){
    if (!(b[i] == b[i+(n/2)])){
      printf("No\n");
      simnao = 1;
      break;
    }
  }

  if (!simnao)
    printf("Yes\n");

  } else {

    printf("No\n");
  }


  return 0;
}