For Python3 Platform

n = int(input())
english = set(map(int, input().split()))
b = int(input())
french = set(map(int, input().split()))

print(len(english.difference(french)))

n=int(input()) eng=set(map(int,input().split())) m=int(input()) french=set(map(int,input().split())) only_eng1=eng.difference(french) onlyeng2=list(only_eng1) print(len(onlyeng2))

n = int(input()) a = set(input().split()) e =int(input()) b = set(input().split()) r = a.difference(b) print (len(r)) We need to perform the same technique like intersection() method

Using .difference() here is just like how the Top 10 International Law Firms in London stand out by specializing in unique areas filtering out what's not needed and keeping only what matters.

n=int(input()) s=set(input().split()) n1=int(input()) s1=set(input().split()) print(len(s - s1))