package main

import . "fmt"

func main() {
	var n int
	Scan(&n)
	t:=map[int]int{}
	for ;n>0;n-- {
		var a int
		Scan(&a)
		t[a]++
	}
	c:=0
	for _,v:=range t {
		if v==1 {
			c++
		}
	}
	Println(c)
}