$3.$ Subnetwork S$,$ to which the computer with IP value $155\mathrm{.}212\mathrm{.}25\mathrm{.}31$ belongs, has a subnet length of $20$ bits. Below wire your answer in dotted decimal.

$(1)$ Write the $4-$byte subnet masking byte in decimal.

$(2)$ Write the $4-$byte subnet address of S$.$

$(3)$ What is the maximum IP value that a host belonging to this subnetwork S can have?

$(4)$ S is divided into $8$ subnetworks of the same size. Calculate the third$-$lowest subnetwork address S$3.$ Hint The lowest subnetwork address $\backslash (\backslash$mathrm$\{$S$\}\_\{1\}\backslash )$ is the same as the subnetwork address S $.$

$(2)$

$(3)$

$(4)$