n = int(input())
m = int(input())
A = list(map(int,input().split()))
ans = [0] * (N + 1)
now = 0
ans[0] = 1
for a in A:
	now += a
	ans[now] = 1
m = int(input())
B = list(map(int,input().split()))
for b in B:
	now -= b
	ans[now] = 1
print(N + 1 - sum(ans))