#include <bits/stdc++.h>
using namespace std;
const int maxn = 1e5 + 5;
int A[maxn], MAX = 0;
int main() {
  int n;
  cin >> n;
  for (int i = 0; i < n; i++) cin >> A[i];
  sort(A, A + n);
  int ans = 0;
  for (int i = 0; i < n; i++)
    if (ans * A[i] + ans <= i) ans++;
  cout << ans;
  return 0;
}
