#include <iostream>

using namespace std;

class Substance
{
protected:
    string name;
    double density;
public:
    Substance(string _name, double _density)
    {
        name = _name;
        density = _density;
    }

    void SetDensity(double _density)
    {
        density = _density;
    }

    void ChangeDensity(double changer)
    {
        density += changer;
    }

    void Display()
    {
        cout << "Name : " << name << endl << "Density: " << density << endl << endl;
    }
};

class Liquid : Substance
{
private:
    double viscosity;
public:
    Liquid(string _name, double _density, double _viscosity) : Substance(_name, _density)
    {
        viscosity = _viscosity;
    }

    void SetViscosity(double _viscosity)
    {
        viscosity = _viscosity;
    }

    void ChangeViscosity(double changer)
    {
        viscosity += changer;
    }

    void Display()
    {
        cout << "Name : " << name << endl << "Density: " << density << endl << "Viscosity: " << viscosity << endl << endl;
    }
};


int main()
{
    Substance* subs1 = new Substance("Bromine", 3120);
    subs1->Display();
    subs1->ChangeDensity(-5);
    subs1->Display();

    Liquid* liq1 = new Liquid("Bromine", 3120, 0.001241);
    liq1->Display();
    liq1->ChangeViscosity(0.024);
    liq1->Display();
}