import Foundation

func readInts() -> [Int] {
    return readLine()!.split(separator: " ").map { Int($0)! }
}

let nk=readInts()
let n=nk[0]
let S=readLine()!

let index=S.index(S.startIndex,offsetBy:n/2)
let T1=S[..<index]
let T2=S[index...]

if (n%2==1)||(T1 != T2){
  print("No")
}else{
  print("Yes")
}