$8\mathrm{.}2(3$ Points$)$ We assume that a file system makes use of the counting approach to managing free blocks in a file system. In this approach, each entry in the counting table stores two items, namely, $(1)$ the address of the first free disk block and $(2)$ the number n of free contiguous disk blocks that follow the first block. Initially, the file system has $512$ GB free space, where the block size is configured to $64$ MB$.$ How many bytes should be reserved in each entry for the second item $($i$.$e$.,$ a counter$)?$