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 n;
char str[110];

int main(){
    scanf("%d%s", &n, str);
    if(n & 1) printf("No\n");
    else{
        int m = n / 2;
        for(int i = 0; i < m; i++){
            if(str[i] != str[i + m]){
                printf("No\n");
                return 0;
            }
        }
        printf("Yes\n");
        return 0;
    }
    return 0;
}