#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, i, p, q, s, j, m, x;
  int a[101] = {0};
  int b[101] = {0};
  cin >> n;
  m = 0;
  for (i = 1; i <= n; i++) {
    cin >> x;
    m = max(m, x);
    a[x]++;
  }
  s = 0;
  for (i = 1; i <= a[0]; i++) b[i] = 1;
  if (a[0] > s) s = a[0];
  for (i = 1; i <= m; i++) {
    j = 1;
    while (a[i] > 0) {
      if (b[j] < i + 1) {
        b[j]++;
        a[i]--;
      } else
        j++;
    }
    if (j > s) s = j;
  }
  printf("%d\n", s);
}
