package main

import (
	"fmt"
)

var (
	N int
	A []int
)

func resolve() int {
	ret := 0
	a := map[int]int{}
	for i := 0; i < N; i++ {
		a[A[i]] += 1
	}
	for _, v := range a {
		if v != 1 {
			continue
		}
		ret += 1
	}
	return ret
}

func main() {
	fmt.Scanf("%d\n", &N)
	A = make([]int, N)
	for i := 0; i < N; i++ {
		fmt.Scanf("%d", &A[i])
	}
	fmt.Println(resolve())
}