int bit_and_for_int_f2(int a, int b) {
    bitset <64> number_one(a);
    //cout << number_one.to_ulong() << " = " << number_one << endl;
    bitset <64> number_two(b);
    //cout << number_two.to_ulong() << " = " << number_two << endl;
    bitset <64> number;
    for (int i = 63; i >= 0; i--) {
        if (number_one[i] == 1) {
            if (number_two[i] == 1) {
                number[i] = 1;
            }
        }
        else {
            number[i] = 0;
        }
    }
    cout << endl << number.to_ulong() << " = " << number;
    return number.to_ullong();
}