import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		// TODO 自動生成されたメソッド・スタブ
		Scanner scan = new Scanner(System.in);
		int n = scan.nextInt();
		List<Integer> list = new ArrayList<Integer>();
		for(int i=0;i<n;i++) {
			list.add(scan.nextInt());
		}
		List<Integer> list2 = new ArrayList<Integer>(new HashSet<>(list));
		System.out.println(list2.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