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

flag = [False]*(N+1)
now = 0
for a in A:
    now += a
    flag[now] = True
for b in B:
    now -= b
    flag[now] = True

print(N+1-sum(flag))