// class D inherit classes A, B and C
class D: public A, B, C

// Calls class specific func impl by using class scope resolution
// Rest is maths 
         void update_val(int new_val)
         {
             int factor = 1;
             while (new_val != 1) 
             {
                factor = !(new_val % 5) ? 5 : !(new_val % 3) ? 3 : 2;
                switch (factor)
                {
                    case 5:
                            C::func(val);
                            break;
                    case 3: 
                            B::func(val);
                            break;
                    default:
                            A::func(val);
                            break;
                }
                new_val = new_val/factor;
             }
          }