import java.util.*;
public class Novelty2{
	public static void main(String... args){
		Scanner scan = new Scanner(System.in);
		int n = scan.nextInt();
		System.out.println(counter(n,scan));
	}
	public static int counter(int n,Scanner scan){
		int[] list = new int[n];
		for(int i = 0; i < n; i++){
			list[i] = scan.nextInt();
		}
		Arrays.sort(list);
		int count=0;
		if(list[0]!=list[1])count++;
		for(int i = 1; i < n; i++){
			if(list[i]!=list[i-1] && list[i]!=list[i+1])count++;
		}
		return count;
	}
}