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>
#include<string.h>

int main () {

    int numb;

    scanf("%d", &numb);

    char words[100];
    char words2[100];
    char words3[100];

    for(int i = 0; i <= numb; i++){
        scanf("%s", words);
    }
    
    int start;

    start = strlen(words);

    printf("%d\n", start);

    for(int i = 0; i <= start/2 - 1; i++){
            words2[i] = words[i + start/2];
            words3[i] = words[i];
    }

     printf("%s\n", words2);
     printf("%s\n", words3);

    if (strcmp(words2, words3) == 0){
        printf("Yes\n");
    }else{
        printf("No\n");
    }

    return 0;
}