N = int(input())
M1 = int(input())
A = list(map(int, input().split()))
M2 = int(input())
B= list(map(int, input().split()))

cnt = 0
s = set([0])
for a in A:
	cnt += a
	s.add(cnt)
for b in B:
	cnt -= b
	s.add(cnt)
print(N+1-len(s))