Combine the following three blocks of addresses into a single block with the same prefix length. The combined block, which uses the minimal address space, should cover all addresses already assigned in the three blocks.

a$.16\mathrm{.}27\mathrm{.}24\mathrm{.}0/26$

$00010000\mathrm{.}00011011\mathrm{.}00011000.$

b$.16\mathrm{.}27\mathrm{.}24\mathrm{.}64/26$

$00010000\mathrm{.}00011011\mathrm{.}00011000\mathrm{.}01000000$

c$.16\mathrm{.}27\mathrm{.}24\mathrm{.}128/25$