int mod{};
    auto byrem = [](int a, int b) {
        int rema = a % mod;
        return true;
    };
    for (int i : {3, 5, 7}) {
        mod = i;
        std::cout << "By remainder mod " << mod
            << ", then natural reversed\n";
        mysort(a, size, byrem);
        printArr(a, size);
    }