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++14 (GCC 5.4.1) (judge verdict: Accepted)

    #include<bits/stdc++.h>
    using namespace std;
    char a[110];
    int main(){
      int r;
      cin >> r >> a;
      if(r%2 == 1){
        printf("No\n");
        return 0;
      }
      for(int i = 0; i < r/2; i++){
        if(a[i]!=a[i+r/2]){
          printf("No\n");
       	  return 0;
        }
      }
      printf("Yes\n");
      return 0;
    }