Mix and match of products

Question

I want to implement mix and match of products in drupal.Suppose if there are three products

Product   Price  
  A        10$  
  B        10$  
  C        10$

I want the mix and match feature of this three products that it is a case of 4(selecting from this three products). The user can select 4 items from three products A,B,C(Lets say A-2,B-1,C-1 OR A-1,B-2,C-1 OR A-2,B-2 OR A-1,C-3). and given a flat rate at 35$ selecting this items. How can we get this functionality this in Ubercart.