package yukicoder;

import java.util.Scanner;

public class Yuki182 {
	
	public static void main(String[] args ) {
		
		Scanner scan = new Scanner(System.in);
		int n = scan.nextInt();
		int a_array[] = new int[n];
		for (int i = 0; i < n ; i++ ) {
			a_array[i] = scan.nextInt();
		}
		scan.close();
		System.out.println(ansArray(a_array));
		
	}
	
	private static int ansArray(int[] arr) {
		int ans_array[] = new int[arr.length];
		
		for(int i = 0; i < arr.length; i++ ){
			
			for(int j = 0; j < arr.length; j++ ){
				
				if(arr[i] == arr[j]){
					ans_array[i]++;
				}
			}
		}
		int ans = 0;
		for(int i = 0; i < ans_array.length; i++ ){
			if(ans_array[i] == 1) {
				ans++;
			}
			
		}
		return ans;
	}
	
}