Eugene, Melvin and David had a total of $260$ stickers. First, Eugene gave Melvin twice as many stickers as Melvin had. Then, Melvin gave David as many stickers as David had. Finally, David gave Eugene as many stickers as Eugene had left. In the end, the ratio of Eugene\textquotesingle s to Melvin\textquotesingle s to David\textquotesingle s stickers was $46:12:7$. How many stickers did Eugene have at first? 
Overseas Competition->Knowledge Point->Counting Modules->Inclusion-Exclusion Principle