#include <bits/stdc++.h>
using namespace std;
int main() {
  long long int n, c;
  cin >> n;
  long long int a[n];
  for (int i = 1; i <= n; i++) {
    cin >> a[i];
  }
  sort(a, a + n);
  c = 0;
  for (int i = 1; i <= n; i++) {
    if (a[i] != a[i + 1]) {
      c++;
    }
  }
  cout << c - 1 << endl;
}
