import java.util.Arrays;
import java.util.Scanner;


public class Main_yukicoder182 {

    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();
        }
        Arrays.sort(a);

        int ret = 0;
        for (int i = 0; i < n; i++) {
        	if (i == 0 && a[i] != a[i + 1]) {
        		ret++;
        	} else if (i == n - 1 && a[i] != a[i - 1]) {
        		ret++;
        	} else if (i > 0 && i < n - 1 && a[i] != a[i - 1] && a[i] != a[i + 1]) {
        		ret++;
        	}
        }

        System.out.println(ret);
        
        sc.close();
    }
}