#include <bits/stdc++.h>
using namespace std;
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  int n;
  cin >> n;
  int arr[n];
  for (int i = 0; i < n; i++) {
    cin >> arr[i];
  }
  sort(arr, arr + n);
  int count = 0;
  for (int i = 1; i < n; i++) {
    if (arr[i - 1] == arr[i]) {
      arr[i - 1] = 0;
    }
  }
  for (int i = 0; i < n; i++) {
    if (arr[i] != 0) {
      count++;
    }
  }
  cout << count;
  return 0;
}
