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: Runtime Error)

        #include<stdio.h>
        #include<string.h>
                                 
                                int main(void){
                                  int n;
                                  int s=0;
                                  scanf("%d/n",&n);
                                  char str[n+1];
                                  
                                  scanf("%s",str);
                                  if((n%2)==0){
                                    char t[(n/2)+1];
                                    for(int i=0;i<(n/2);i++){
                                    t[i]=str[i];
                                    }
                                    strcat(t,t);
                                    if(str==t){
                                     s=1;
                                    }
                                  }
                                  if(s==1){
                                  printf("Yes\n");
                                  }
                                  if(s==0){
                                  printf("No\n");
                                  }
                                 return 0; 
                                }