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

int main() {
    int pages_amount, book_size;

    std::cin >> pages_amount;
    std::vector<int> pages(pages_amount);

    for (int & page : pages) {
        std::cin >> page;
    }
    std::cin >> book_size;

    int ub = *std::max_element(pages.begin(), pages.end());
    std::vector<int> vol(book_size);
    std::function<bool(int, int)> foo = [&](int p, int q) {
        for (; p >= q && vol[q] + pages[p] <= ub; --p) vol[q] += pages[p];
        return !q ? p < q : foo(p, q - 1);
    };
    for (; !foo(pages_amount - 1, book_size - 1); ++ub) {
        vol.assign(book_size, 0);
    }
    std::cout << *std::max_element(vol.begin(), vol.end());

    return 0;
}