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++14 (GCC 5.4.1) (judge verdict: Accepted)


#include<bits/stdc++.h>
using namespace std;
typedef long long ll;


int main()
{
    
   ll r;
   cin>>r;
   string s;
   cin>>s;
   ll c=0;
   if(1&r)
    cout<<"No";
   else
    {
    	for(ll i=0;i<r/2;i++)
    	  {
    	  	if(s[i]==s[r/2 +i])
    	  	c++;
		  }
		  if(c==r/2)
		    cout<<"Yes";
		  else
		   cout<<"No";
	}
  return 0;
    
}