// yukicoder: No.182 新規性の虜
// 2019.4.13 bal4u

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

//// 高速入力
#if 1
int getchar_unlocked();
#define gc() getchar_unlocked()
#else
#define gc() getchar()
#endif
int in()    // 非負整数の入力
{
	int n = 0, c = gc();
	do n = 10 * n + (c & 0xf), c = gc(); while (c >= '0');
	return n;
}

int a[100005]; int N;

void Qsort(int *a, int l, int r) {
	int i, j, m, t;
	
	i = l, j = r, m = a[(l+r) >> 1];
	while (1) {
		while (a[i] < m) i++;
		while (m < a[j]) j--;
		if (i >= j)	break;
		t = a[i], a[i] = a[j], a[j] = t;
		i++, j--;
	}
	if (l+1 < i) Qsort(a, l, i-1);
	if (j+1 < r) Qsort(a, j+1, r);
}

int main()
{
	int i, ans;

	N = in();
	for (i = 1; i <= N; i++) a[i] = in();
	Qsort(a, 1, N);
	ans = 0;
	for (i = 1; i <= N; i++) {
		if (a[i] != a[i - 1] && a[i] != a[i + 1]) ans++;
	}
	printf("%d\n", ans);
	return 0;
}