import java.util.*;
import java.lang.*;

public class Main {
    public static void main(String[] args) {
        Scanner dataScanner = new Scanner(System.in);
        int numLayers = Integer.parseInt(dataScanner.nextLine());
        HashSet<Integer> diameter = new HashSet<Integer>();
        for (int i = 0; i < numLayers; i++) {
            diameter.add(Integer.parseInt(dataScanner.nextLine()));
        }
        System.out.println(diameter.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