#include <algorithm>
#include <cstdio>
#include <iostream>
#include <map>
#include <set>
#include <string>
#include <unordered_map>
#include <vector>
#define rep(i, n) for (int i = 0; i < n; ++i)
#define FOR(i, a, b) for (int i = a; i < b; ++i)
#define ll long long
#define pb(x) push_back(x)
using namespace std;

int main() {
  unordered_map<int, bool> mp;
  int n;
  cin >> n;
  int a[100000];
  rep(i, n) cin >> a[i];
  sort(a, a + n);
  int cnt = 0;
  if (a[0] != a[1]) cnt++;
  FOR(i, 1, n - 1) if (a[i - 1] != a[i] && a[i] != a[i + 1]) cnt++;
  if(a[n - 1] != a[n - 2]) cnt++;
  cout << cnt << endl;
  return 0;
}