import java.util.*;
import java.io.InputStreamReader;
import java.io.BufferedReader;


public class Main {
    public static void main(String[] args) throws Exception {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        int N = Integer.parseInt(br.readLine());
        String[] sa = br.readLine().split(" ");
        Map<Integer, Integer> m = new HashMap<>();
        for (int i = 0; i < N; i++) {
            int A = Integer.parseInt(sa[i]);
            m.merge(A, 1, Integer::sum);
        }
        long ans = m.values().stream().filter(e -> e == 1).count();
        System.out.println(ans);
    }    
}