import java.util.*;
 
public class Main {
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        int N = sc.nextInt();
        int[] a = new int[N];
        
        for(int i=0; i<N; i++){
            a[i] = sc.nextInt();
        }
        
        TreeSet <Integer> tree = new TreeSet <Integer> ();
        for(int i=0; i<N; i++){
            tree.add(new Integer(a[i]));
        }
        System.out.println(tree.size());
    }
}
/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz