code for multiple inheritance using public scope and use of protected access specifiers

#include <iostream>
using namespace std;

class stu
{
   int id;
   char name[10];
   
   public:
   void get_data()
   {
       cout<<"enter student name:";
       cin>>name;
       cout<<"enter student id:";
       cin>>id;
   }
   void put_data()
   {
       cout<<"name="<<name;
       cout<<"id="<<id;
       
       
   }
};


class marks
{
   protected:
   int m1,m2,m3;
   public:
   void getmarks()
   {
       cout<<"enter three sub marks:";
       cin>>m1>>m2>>m3;
   }
  void putmarks()
  {
      cout<<"m1="<<m1;
      cout<<"m2="<<m2;
      cout<<"m3="<<m3;
  }
    
    
};
class result:public stu,public marks
{
    int total;
    float avg;
    public:
    void show()
    {
    
    getmarks();
    total= m1+m2+m3;
    cout<<"total marks:"<<total<<endl;;
    avg=total/3.0;
    cout<<"average marks scored:"<<avg<<endl;
    
}
    
    
};
int main()
{
    
    result r[3];
    for (int i=0;i<3;i++)
    {
    cout<<"data of student"<<i+1<<":"<<endl;
    r[i].show();
    }
    return 0;
    
    
}