#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, a[101] = {0};
  cin >> n;
  for (int i = 0; i < n; i++) {
    int x;
    cin >> x;
    a[x]++;
  }
  int ans = a[0], cf = a[0], temp = a[0];
  for (int i = 1; i <= 100; i++) {
    cf = cf + a[i];
    temp = cf / (i + 1);
    if (cf % (i + 1) != 0) temp++;
    if (temp > ans) ans = temp;
  }
  cout << ans;
  return 0;
}
