#include <bits/stdc++.h>

#define rep(i, ss, ee) for (int i = ss; i < ee; ++i)
using namespace std;

int N;
vector<int> v;

void input() {
  cin >> N;
  v.resize(N);
  for (auto &e : v) cin >> e;
  sort(v.begin(), v.end());
}

void solve() {
  int ans = 0;
  rep(i, 1, N - 1) if (v[i - 1] != v[i] && v[i] != v[i + 1]) ans++;
  if (v[0] != v[1] ) ans++;
  if (v[N-1] != v[N-2] ) ans++;
  cout << ans << endl;
}

int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  input();
  solve();
  getchar();
}