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)

/* ABC145-B
   Takatan */

#include<stdio.h>
#include<stdlib.h>
int main(void){
    int length, i;
    char *string;

    scanf( "%d" , &length);
    string = malloc(sizeof(char) * (length+1));
    scanf( "%s" , string);

    for(i=0; i < length/2; i++){
        if(string[i]!=string[length/2+i] || length%2==1){
            printf( "No\n" );
            return 0;
        }
    }
    printf( "Yes\n" );
    return 0;
}