C++ Programming - Functions - Discussion

#include<iostream.h> 
static double gDouble; 
static float  gFloat; 
static double gChar; 
static double gSum = 0; 
class BaseOne
{
    public:
    void Display(double x = 0.0, float y = 0.0, char z = 'A')
    {
        gDouble = x;
        gFloat  = y;
        gChar   = int(z);
        gSum    = gDouble + gFloat + gChar;
        cout << gSum; 
    }
};
class BaseTwo
{
    public: 
    void Display(int x = 1, float y = 0.0, char z = 'A')
    {
        gDouble = x;
        gFloat  = y;
        gChar   = int(z); 
        gSum    = gDouble + gFloat + gChar;
        cout << gSum;
    }
};
class Derived : public BaseOne, BaseTwo
{
    void Show()
    {
        cout << gSum;
    } 
}; 
int main()
{
    Derived objDev;
    objDev.BaseTwo::Display(10, 20, 'Z');
    return 0; 
}