C++ Class Inheritance Multiple inheritance with publication class

#include <iostream>
#include <string>
using namespace std;
class publication
{
   private://from w ww . jav  a 2  s  . c  om
   string title;
   float price;
   public:
   void getdata()
   {
      cout << "\nEnter Title:C++  "; cin >> title;
      cout << "   Enter price: "; cin >> price;
   }
   void putdata() const
   {
      cout << "\nTitle:C++  " << title;
      cout << "\n   Price: " << price;
   }
};
class sales
{
   private:
   enum { MONTHS = 3 };
   float salesArr[MONTHS];
   public:
   void getdata();
   void putdata() const;
};
void sales::getdata()
{
   cout << "   Enter sales for 3 months\n";
   for(int j=0; j<MONTHS; j++)
   {
      cout << "      Month " << j+1 << ": ";
      cin >> salesArr[j];
   }
}
void sales::putdata() const
{
   for(int j=0; j<MONTHS; j++)
   {
      cout << "\n   Sales for month " << j+1 << ": ";
      cout << salesArr[j];
   }
}
class book : private publication, private sales
{
   private:
   int pages;
   public:
   void getdata()
   {
      publication::getdata();
      cout << "   Enter number of pages: "; cin >> pages;
      sales::getdata();
   }
   void putdata() const
   {
      publication::putdata();
      cout << "\n   Pages: " << pages;
      sales::putdata();
   }
};
class tape : private publication, private sales
{
   private:
   float time;
   public:
   void getdata()
   {
      publication::getdata();
      cout << "   Enter playing time: "; cin >> time;
      sales::getdata();
   }
   void putdata() const
   {
      publication::putdata();
      cout << "\n   Playing time: " << time;
      sales::putdata();
   }
};
int main()
{
   book book1;        // define publications
   tape tape1;
   book1.getdata();   // get data for publications
   tape1.getdata();
   book1.putdata();   // display data for publications
   tape1.putdata();
   cout << endl;
   return 0;
}