import java.util.*;

public class Main {

	public static void main(String[] args) {

		//フィールド
		int n = 0;
		ArrayList<Integer> uniqueList = new ArrayList<Integer>();
		//リスト作成
		Scanner scanner = new Scanner(System.in);
		n = scanner.nextInt();
		ArrayList<Integer> intList = new ArrayList<Integer>();
		for(int i = 0; i < n; i++) {
			int x = scanner.nextInt();
			intList.add(x);
		}


		System.out.println(new HashSet<>(intList).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