import java.util.Scanner;
public class Main 
{
	public static void main(String[] args) 
	{
		Scanner in=new Scanner(System.in);
		int n=in.nextInt();
        int []arr=new int [n];
        int m=n;
        for(int i=0;i<n;i++){
            arr[i]=in.nextInt();
        }
        for(int i=0;i<n-1;i++){
            for(int j=i+1;j<n;j++){
                if(arr[i]==arr[j]){
                    m--;
                    break;
                }
            }
        }
        System.out.println(m);
    }
}