i=input
i()
W=set(map(int,i().split()))
i()
B=set(map(int,i().split()))
w,b=1,1
c=0
for x in sorted(list(W|B)):
	if x in W and x in B: c+=1; w,b=b,w
	elif x in W and b: c+=1; w,b=1,0
	elif x in B and w: c+=1; w,b=0,1
print(c)