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 Scala (2.11.7) (judge verdict: Accepted)

object Main extends App {
  val n =  scala.io.StdIn.readInt()
  val s = scala.io.StdIn.readLine()
  if (n % 2 == 0) {
    val splitLength = n / 2
    val before = s dropRight splitLength
    val after = s drop splitLength
    if (before == after) {
      println("Yes")
    } else {
      println("No")
    }
  } else {
    println("No")
  }
}