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){
        int n,i,c;
        char a[100];
        char b[50];
        scanf("%d",&n);

        scanf("%s",a);

        c=n/2;
        if(n%2){
          printf("No\n");
          return 0;
        }
        for(int i=0;i<n/2;i++){
          if(a[i]!=a[i+c]){
            printf("No\n");
            return 0;
          }
        }
        printf("Yes\n");
        return 0;
      }