#include <algorithm>
#include <iostream>
#include <vector>

int main() {
    using namespace std;
    int n, s;
    cin >> n >> s;
    long long tot = 0;
    vector<int> a(n);
    for (auto &e : a) {
        cin >> e;
        tot += e;
    }
    sort(a.rbegin(), a.rend());

    auto pred = [&](long long m) -> bool {
        vector<int> large;
        int res = 0;
        for (auto e : a) {
            if (e <= m) {
                res++;
            } else {
                if (large.size() % m == 0) { res += e + 1; } 
                large.push_back(e);
            }
        }
        return res <= s;
    };

    long long ok = tot, ng = 0;
    while (ok - ng > 1) {
        long long mid = (ok + ng) / 2;
        if (pred(mid)) {
            ok = mid;
        } else {
            ng = mid;
        }
    }
    cout << ok << endl;
}