#include <stdio.h>
#include <stdlib.h>
#include <string.h>

int main(void)
{
	int n, *a;
	char str[10000], *ch;
	scanf("%d%*c", &n);
	a = malloc(sizeof(int)*n);
	fgets(str, sizeof(str), stdin);
	ch = strtok(str, " \n");
	for (int i = 0; i < n; i++) {
		if (ch == NULL) break;
		else a[i] = atoi(ch);
		ch = strtok(NULL, " \n");
	}
	int x, sum = 0;
	for (int i = 0; i < n; i++) {
		x = 0;
		for (int j = 0; j < n; j++) if (a[i] == a[j]) x++;
		if (x > 1) sum++;
	}
	sum = n - sum;
	printf("%d\n", sum);
	free(a);
	return 0;
}