#include <bits/stdc++.h>
using namespace std;
const int maxn = 1e2 + 5;
int a[maxn];
int bo[maxn];
int fin[105];
int main() {
  int n;
  cin >> n;
  for (int i = 1; i <= n; i++) {
    cin >> a[i];
    bo[a[i]]++;
  }
  sort(a + 1, a + n + 1);
  int maxx = 1;
  int i = 0;
  while (n) {
    int k = 1;
    while (bo[a[i]]) {
      if (a[i] < fin[k]) {
        k++;
      }
      fin[k]++;
      bo[a[i]]--;
      n--;
    }
    i++;
    if (k > maxx) {
      maxx = k;
    }
  }
  cout << maxx << endl;
  return 0;
}
