#include <bits/stdc++.h>
using namespace std;
const long long MAX = 1e6 + 8;
const long long N = 1e5 + 5;
void f_io() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  ;
}
int32_t main() {
  f_io();
  long long t = 1;
  while (t--) {
    long long n;
    cin >> n;
    vector<long long> strength(n);
    for (long long i = 0; i < n; i++) cin >> strength[i];
    sort(strength.begin(), strength.end());
    long long ans = 1;
    for (long long i = 0; i < n; i++)
      if (strength[i] < i / ans) ans++;
    cout << ans << "\n";
  }
}
