fun main(args :Array<String>){
  var input:String?=readLine()
  var first:String? =""
  var second:String? = ""
  var num:Int = input!!.length
  var index:Int = 0
  input!!.forEach{
    if (index<=(num-1)/2-1){
      first += it.toString()
      index++
    }else if(index>=(num+3)/2-1){
      second += it.toString()
      index++
    }else{
      index++
    }
  }
  if(first==second){
    println("Yes")
  }else{
    println("No")
  }
}