Convert the following formula to conjunctive normal form:

$($Negation p $->$ negation q$)->($r $->$ negation s$)$

Hint. You may find the following logical equivalence helpful: A $->$ B $=-$ A v B$.$

$($b$)$ Convert your formula from part $($a$)$ to a formula in clausal form.

c$)$ Is your formula from parts $($a$)$ and $($b$)$ satisfiable? If so$,$ give a satisfying assignment of truth values to the propositions p$,$ g$,$ r$,$ and s$.$ If not, explain why.

Note. You do not need to use the method of resolution to answer this question.

Note: a formula is in conjunction normal form if it consists of a conjunction of disjunction of literals