Problem $3(10$ points$)$: A large number of consecutive IP addresses are available starting at $198\mathrm{.}16\mathrm{.}0\mathrm{.}0.$

Suppose that four organizations: A$,$ B$,$ C$,$ and D$,$ request $4000,2000,4000,$ and $8000$ addresses,

respectively, and in that order.

For each of the blocks allocated for A and B only, give the $(1)$ first IP address assigned, $(2)$ the last IP

address assigned, and $(3)$ the mask in the w$.$x$.$y$.$z$/$s notation. It is required to allocate the block A at

the base address $198\mathrm{.}16\mathrm{.}0\mathrm{.}0,$ and the block for B is allocated right after Block A with zero gap.

Hint: round the block sizes to the nearest larger power of $2.$