I,i=input,int;n,s,t=i(I()),list(map(i,I().split())),list(map(i,I().split()));S,T,X,Y=s.count(2),t.count(2),0,0;X+=0if T else s.count(1);Y+=0if S else t.count(1);print(n*(S+T)-S*T+max(X,Y))