Admins and Shopping

CodeChef admins went on shopping at a shopping mall. There are $N$ shops in the mall where the $i^{th}$ shop has a capacity of $A_i$ people. In other words, at any point in time, there can be **at most** $A_i$ number of people in the $i^{th}$ shop. There are $X$ admins. Each admin wants to visit each of the $N$ shops **exactly once**. It is known that an admin takes exactly **one** hour for sho