import java.util.*;

public class Main {
	static Scanner sc = new Scanner(System.in);
	public static void main(String[] args) {
		Map<Integer,Integer> map = new HashMap<>();
		int n = sc.nextInt();
		for (int i=0; i<n; i++) {
			int temp = sc.nextInt();
			map.put(temp,map.getOrDefault(temp,0));
			map.put(temp,map.get(temp)+1);
		}
		
		int num = 0;
		for (Map.Entry<Integer,Integer> entry : map.entrySet()) {
			if (entry.getValue()==1) {num++;}
		}
		
		System.out.println(num);
	}
}