#include <bits/stdc++.h>
using namespace std;
bool comp(int x, int y) { return x > y; }
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  ;
  int tt = 1;
  int m = INT_MIN, n, k;
  string st;
  while (tt--) {
    cin >> n;
    int arr[n], mx[101] = {0}, count[101] = {0};
    for (long long i = 0; i < n; i++) {
      cin >> arr[i];
      mx[arr[i]] += 1;
    }
    sort(arr, arr + n);
    int i = 0;
    while (n > 0) {
      int k = 1;
      while (mx[arr[i]] > 0) {
        if (arr[i] < count[k]) ++k;
        ++count[k];
        n--;
        --mx[arr[i]];
        if (k > m) m = k;
      }
      ++i;
    }
    cout << m << endl;
  }
}
