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 int ll;

int main()
{
    string s,s1,s2;
    int n,i;
    cin>>n;
    cin>>s;
    s1="";
    s2="";
    for(i=0;i<n/2;i++)
    {
        s1+=s[i];
    }
    for(i=n/2;i<n;i++)
    {
        s2+=s[i];
    }
    if(s1==s2)
        cout<<"Yes"<<endl;
    else
        cout<<"No"<<endl;
    return 0;
}