(* N is a protected sympol in mathematica so we use NN=pq, e=7*)

e=7;
NN=;

(* c= PowerMod[50,d,p q] *)

c=PowerMod[50,,NN]

Clear[cprime]
cprime = c(* ??? currently, incorrect fill in the blank with the correct answer *)

(*Check if your solution is correct, output should be 0 *)
PowerMod[cprime,e,NN] - 6400