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