package main

import "fmt"

var f [200001]bool

func main()  {
	var n,a int
	fmt.Scan(&n)
	c := 0
	for ; n>0 ; n-- {
		fmt.Scan(&a)
		if f[a] {
			c++
		}
		f[a] = !f[a]
	}
	fmt.Println(c)
}