#include <bits/stdc++.h>
using namespace std;
const int N = 200;
long long n, num[N], tmp;
int main() {
  cin >> n;
  for (int i = 0, v; i < n; i++) cin >> v, num[v]++;
  for (int i = 1; i <= 100; i++) {
    for (int j = 1; j < i; j++)
      tmp = max(0ll, min(num[0] - num[j], num[i])), num[j] += tmp,
      num[i] -= tmp;
    tmp = num[i] - num[0];
    int k = tmp % (i + 1);
    tmp = tmp / (i + 1);
    if (tmp > 0 || k > 0)
      for (int j = 0; j <= i; j++) {
        num[j] += tmp, num[i] -= tmp;
        if (j < k) num[j]++, num[i]--;
      }
  }
  cout << num[0] << endl;
}
