import java.util.Arrays;
import java.util.Scanner;

public class Main{
	public static void main(String[] args){
		Scanner sc=new Scanner(System.in);
		while(sc.hasNext()){
			int n=sc.nextInt();
			int[] a=new int[n];
			for(int i=0;i<n;i++) a[i]=sc.nextInt();
			Arrays.sort(a);
			int ans=0;
			for(int i=0;i<n;i++){
				ans++;
				if(i+1<n && a[i]==a[i+1]) ans--;
				while(i+1<n && a[i]==a[i+1]){
					i++;
				}
			}
			System.out.println(ans);
		}
	}
}