import java.util.HashSet;
import java.util.Scanner;
import java.util.Set;

public class Main {

    public static void main(final String[] args) {
        final Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        Set<Integer> s = new HashSet<>();
        int d = 0;

        for(int i=0; i<n; i++){
            d = sc.nextInt();
            if(!s.contains(d)){
                s.add(d);
            }
        }
        System.out.println(s.size());
        sc.close();
    }
}
/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