import java.util.Scanner;

public class Main {
    private static int getUniqueCount(int a[], int n) {
        int res = 0; //数组前n个数中的不同数的个数
        for (int i = 0; i < n; i++) {
            boolean flag = true;
            for (int j = 0; j < i; j++) {
                if (a[i] == a[j]) //说明当前元素a[j]不是第一次出现的
                    flag = false;
            }
            if (flag) //说明a[i]是第一次出现
                res++;
        }
        return res;
    }

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int[] a = new int[n];
        for (int i = 0; i < n; i++) {
            a[i] = sc.nextInt();
        }
        System.out.println(getUniqueCount(a, n));
    }
}