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: Wrong Answer)

#include <stdio.h>
int main(void){
    // Your code here!
    int n;
    char S[100];
    scanf("%d",&n);
    scanf("%s",&S);
    if(n%2 ==1){
        printf("No");
    }
    else if(n==2){
        if(S[0]==S[1]){
            printf("Yes");
        }
        else {printf("No");}
    }
    else {
        if(S[0] != S[n/2]){
            printf("No");
        }
        else if(S[1] != S[n/2 + 1] || S[2] != S[n/2 + 2]){
            printf("No");
        }
        else {
            printf("Yes");
        }
    }
    return 0;
}