import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int N = sc.nextInt();
        Map<Integer, Integer> m = new HashMap<>();
        for (int i = 0; i < N; i++) {
            int A = Integer.parseInt(sc.next());
            // int A = sc.nextInt();
            m.merge(A, 1, Integer::sum);
        }
        long ans = m.values().stream().filter(e -> e == 1).count();
        System.out.println(ans);
    }    
}