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 Kotlin (1.0.0) (judge verdict: Accepted)

import java.util.*;

fun main(args: Array<String>) {
   readLine()!!.toInt()
   var s= readLine()!!.toString()
   var slen = s.length
   var x = slen % 2
   if(x == 0){
   var slen2 = slen / 2
   var ssub = s.substring(0,slen2)
   var lastsub = s.substring(slen2,slen)
   if(ssub == lastsub){
      println("Yes")
   }else{println("No")}
   
   
   
   } else {
      println ("No")
   }





}