#include <bits/stdc++.h>
using namespace std;
int n, arr[102], pile;
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cin >> n;
  for (int i = 0; i < n; i++) {
    cin >> arr[i];
    arr[i]++;
  }
  sort(arr, arr + n);
  for (int i = 0; i < n; i++)
    if (pile * arr[i] <= i) pile++;
  cout << pile << endl;
  return 0;
}
