#include <bits/stdc++.h>
using namespace std;
int n, a[101], piller;
int main() {
  cin >> n;
  for (auto i = 0; i < n; i++) cin >> a[i];
  sort(a, a + n);
  for (auto i = 0; i < n; i++) {
    if (piller * a[i] + piller <= i) piller++;
  }
  cout << piller;
}
