Class to class conversion

#include<iostream>
using namespace std;
class dollar
{
    int d;
    public:
        int get_data()
        {
            cout<<"\n Enter dollar";
            cin>>d;
            return d;
        }
};
class rupee
{
    int rs;
    public:
        rupee()
        {
            rs=0;
        }
        rupee(dollar d)
        {
            rs=d.get_data()*73;
        }
        void disp()
        {
            cout<<"\n Rupee is "<<rs;
        }
};
int main()
{
    rupee r;
    dollar d;
    r=d;//convestion from one class to another
    r.disp();
}