Virtual base class C++ Program to convert a Octal number to a Decimal

Write a program in C++ to convert a Octal number to a Decimal number by using the virtual base class in object oriented programming.

#include<iostream>
#include<math.h>
using namespace std;
class a
{ 
    protected:
	int rem,T4Tutorials_Octal,count;
};
class b:virtual public a
{ 
  protected:
  int T4Tutorials_Octal;
};
class c:public b
{
	public:
	int input()
	{
	cout<<"Please Enter an octal number:";
	cin>>T4Tutorials_Octal;
	}
	int show()
	{
		int decimalnumber=0;
		for(count=0;T4Tutorials_Octal>0;count++)
	{
		rem = T4Tutorials_Octal%10;
		decimalnumber = decimalnumber+ rem*pow(8,count);
		T4Tutorials_Octal=T4Tutorials_Octal/10;
	}
		cout<<"decimal equivalent is"<<decimalnumber;
	}
};
int main()
{
	c obj;
	obj.input();
	obj.show();
}

Output

Please Enter an octal number: 9

decimal equivalent is 9