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()
 {
     int N;
      scanf("%d",&N);
      if(N==1)
      printf("No");
      else
      {
     char s[N+5];
    
     scanf("%s",s);
     int flag=0;
     for(int i=0;i<N/2;i++)
     {
         if(s[i]!=s[i+N/2])
         {
             flag=1;
             break;
         }
     }
     if(flag==1)
     printf("No");
     else
     printf("Yes");
      }
     return 0;
 }