Калькулятор/перебор/2.0

// 26 pts https://informatics.msk.ru/moodle/mod/statements/view3.php?chapterid=113440#1

# include <iostream>
# include <vector>

void search(size_t &n, size_t &a, size_t &b, size_t &c, size_t &min_ans, std::vector<size_t> cur) {
    if (cur.size() == a + b + c) {
        size_t n_copy = n;
        size_t count_a = 0;
        size_t count_b = 0;
        size_t count_c = 0;
        for (auto i : cur) {
            if (i == 0) {
                count_a++;
                n_copy /= 2;
            } else if (i == 1) {
                count_b++;
                n_copy = (n_copy + 1) / 2;
            } else {
                count_c++;
                if (n_copy != 0) {
                    n_copy = (n_copy - 1) / 2;
                }
            }
        }
        if (count_a == a && count_b == b && count_c == c) {
            min_ans = std::min(min_ans, n_copy);
        }
    } else {
        cur.push_back(0);
        search(n, a, b, c, min_ans, cur);
        cur.pop_back();
        cur.push_back(1);
        search(n, a, b, c, min_ans, cur);
        cur.pop_back();
        cur.push_back(2);
        search(n, a, b, c, min_ans, cur);
    }
}
int main() {
    size_t n, a, b, c;
    std::cin >> n >> a >> b >> c;
    size_t ans = n;
    std::vector<size_t>cur;
    search(n, a, b, c, ans, cur);
    std::cout << ans;
    return 0;
}