func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     int n, tmp;     cin >> n;     multiset<int> a;     for (int i = 0; i < n; i++) {       cin >> tmp;       a.insert(tmp);     }     int ans = 0;     while (!a.empty()) {       int h = 0;       while (a.lower_bound(h) != a.end()) {         a.erase(a.lower_bound(h));         h++;       }       if (h) ans++;     }     cout << ans << endl;     return 0;   }   