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 9.2.1) (judge verdict: Accepted)

//  cd Desktop/Atcoder
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define rep(i,n) for(i=0;i<(n);i++)
#define ll long long
#define ull unsigned long long
#define MOD 1000000007

int main(){
    int n,i;
    char s[102]={};
    scanf("%d",&n);
    scanf("%s",s);
    if (n%2!=0){
        printf("No");
        return 0;
    }
    rep(i,n/2){
        if (s[i]!=s[i+n/2]){
            printf("No");
            return 0;
        }
        
    }
    printf("Yes");
    return 0;
}