#include <bits/stdc++.h>
using namespace std;
const long long MXN = 1e6 + 1;
const long long MNN = 1e3 + 1;
const long long MOD = 1e9 + 7;
const long long INF = 1e18;
const long long MAGIC = 1000;
const long double EPS = 1e-9;
const long double PI = 3.1415926536;
const string TIME = "rovno_ushten_push_ketti";
long long n;
long long a[MXN];
int main() {
  ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);
  cin >> n;
  for (long long i = 0; i < n; i++) {
    cin >> a[i];
  }
  sort(a, a + n);
  for (long long i = 1; i <= n; i++) {
    bool ok = 1;
    for (long long j = 0; j < n; j++) {
      if (a[j] < j / i) {
        ok = 0;
      }
    }
    if (ok) {
      cout << i;
      return 0;
    }
  }
  return 0;
}
