#include <bits/stdc++.h>

using namespace std;

#define all(X) (X).begin(), (X).end()
#define pb push_back
#define rall(X) (X).rbegin(), (X).rend()
#define ll long long
#define ull unsigned long long
#define ld long double
#define fir first
#define sec second

int main() {
	ll n; cin >> n;
	vector<ll> a(n);
	for (ll i = 0; i < n; i++) {
		cin >> a[i];
	}
	sort(rall(a));

	ll l = 0, r = n;
	while (r - l > 1) {
		ll tm = (l + r) / 2;
		vector<ll> b(tm, 1e9);
		bool ch = true;
		for (ll i = 0; i < n; i += tm) {
			for (ll j = i; j < min(i + tm, n); j++) {
				if (b[j - i] == 0) {
					ch = false;
					break;
				}
				b[j - i] = min(b[j - i] - 1, a[j]);
			}
		}
		if (ch == true) {
			r = tm;
		} else {
			l = tm;
		}
	}

	if (l == 0) {
		cout << r << '\n';
		return 0;
	}
	vector<ll> b(l, (ll)1e9);
	bool ch = true;
	for (ll i = 0; i < n; i += l) {
		for (ll j = i; j < min(i + l, n); j++) {
			if (b[j - i] == 0) {
				ch = false;
				break;
			}
			b[j - i] = min(b[j - i] - 1, a[j]);
		}
	}
	if (ch == true) {
		cout << l;
	} else {
		cout << r;
	}

	return 0;
}