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(){
    char str[200];
    int i=0,s=0,length,half;

    scanf("%d",&length);
    scanf("%s",str);
    half=length/2;
    
    if(length%2==0){

    while(i<half){
      if(str[i]==str[half+i]){
        i++;
      }
      else{
        s++;
        printf("No\n");
        break;
      }
    }
    if(s==0){
     printf("Yes\n");
    }
    }
else{
printf("Yes\n");
}
    return 0;
  }