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<math.h>
                 
                int main(){
                  int n,i;
                  char s[n+1];
                  scanf("%d %s",&n,s);
                  if(n%2 == 0){
                    for(i=0;i<n/2;i++){
                      if(s[i] != s[i+n/2]){
                        puts("No");
                        return 0;
                      }
                    }
                      puts("Yes");
                    return 0;
                  }
                  else{
                    puts("No");
                    return 0;
                  }
                }