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

public class Main {

	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		Set<Integer> list = new HashSet<>();		// 整数列

		int num = scan.nextInt();					// 整数の個数
		for(int i = 0; i < num; i++) {
			list.add(scan.nextInt());
		}

		System.out.println(list.size());

		scan.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