Калькулятор/DP

// OK B region first day 16/17 https://informatics.mccme.ru/mod/statements/view3.php?id=24702&chapterid=113440#

#include <iostream>
#include <vector>
#include <limits>

int main() {
    uint64_t n;
    size_t a, b, c;
    std::cin >> n >> a >> b >> c;
    std::vector<std::vector<std::vector<uint64_t>>> m(a + 1);
    for (size_t i = 0; i <= a; i++) {
        m[i].resize(b + 1);
        for (size_t j = 0; j <= b; j++) {
            m[i][j].resize(c + 1);
            for (size_t k = 0; k <= c; k++) {
                m[i][j][k] = std::numeric_limits<uint64_t>::max();
            }
        }
    }
    m[0][0][0] = n;

    for (int32_t i = 0; i <= a; i++) {
        for (int32_t j = 0; j <= b; j++) {
            for (int32_t k = 0; k <= c; k++) {
                if (i + j + k == 0) continue;
                if (i != 0) {
                    m[i][j][k] = m[i - 1][j][k] / 2;
                }
                if (j != 0 && m[i][j][k] > (m[i][j - 1][k] + 1) / 2) {
                    m[i][j][k] = (m[i][j - 1][k] + 1) / 2;
                }
                if (k != 0 && m[i][j][k] > (m[i][j][k - 1] - 1) / 2) {
                    m[i][j][k] = (m[i][j][k - 1] - 1) / 2;
                }
            }
        }
    }
    std::cout << m[a][b][c];
    return 0;
}