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(void)
{
  short int N;
  char S[100];
  short int i;
  
  scanf("%hd",&N);
  scanf("%s",S);
  
  if(N%2==1){
    printf("No");
    return 0;
  }else{
    for(i=0;i<N/2;i++){
      if(S[i]!=S[i+N/2]){
        printf("No");
        return 0;
      }
    }
  }
    printf("Yes");
    return 0;
}