import java.util.HashSet;
import java.util.Scanner;
     
class Main{
    public static void main(String arg[]) {
        Scanner sc = new Scanner(System.in);
        int N = sc.nextInt();
        HashSet<Integer> hs = new HashSet<Integer>();

        for(int i = 0; i < N; i++) {
            hs.add(sc.nextInt());
        }

        sc.close();

        System.out.println(hs.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