dx

#include<iostream>
using namespace std;
            class student_general_marks{
            protected:
            int roll;
            float sub1;
            float sub2;
public:
        void general(){
        cout<<"enter roll no"<<endl ;
        cin>> roll;
        cout<<"marks for sub1"<<endl;
        cin>>sub1;
        cout<<"marks for sub2"<<endl;
        cin>>sub2;
        }
};
                            class student_cpp_marks
                                  {
                            protected:
                            float cpp_marks;
                            public:
                            void programming ()
                            {
                            cout <<"marks for cpp"<<endl ;
                            cin>>cpp_marks;
                            }
                                };
                                                class result : public student_general_marks,public student_cpp_marks
                                                   {
                                                protected:
                                                float a;
                                                public:
                                                void resultdisplay ()
                                                {
                                                a=(sub1+sub2+cpp_marks)/3.00;
                                                cout<<"average is"<<a;
                                                }
                                                    };
int main(){
                            result R;
                            R.general();
                            R.programming();
                            R.resultdisplay();
                            return 0;
}