#include <iostream>
#include <numeric>
#include <algorithm>
#include <string>
#include <vector>
#include <cmath>
#include <queue>

#define rep(i, a) FOR(i, 0, a)
#define FOR(i, a, b) for(int i = a; i < b; ++i)

int a[100001];

int main(){
	int n;
	std::cin >> n;
	rep(i, n)std::cin >> a[i];
	std::sort(a, a + n);
	int cnt = 0;
	if (n == 1)++cnt;
	if (n >= 2 && a[0] != a[1])++cnt;
	FOR(i, 1, n - 1){
		if (a[i] != a[i + 1] && a[i] != a[i - 1])++cnt;
	}
	if (n >= 2 && a[n - 2] != a[n - 1])++cnt;
	std::cout << cnt << std::endl;
	return 0;
}