fun main(args: Array<String>){
    val n = readLine()!!.toInt()
    val aList = readLine()!!.split(" ").map{ it.toLong() }
    val map = mutableMapOf<Long, Int>().withDefault{ 0 }
    for (a in aList){
        map[a] = (map[a]?:0) + 1
    }
    println(map.filter{ it.value == 1}.size)
}