N = int(input())
M1 = int(input())
Am = list(map(int, input().split()))
M2 = int(input())
Bm = list(map(int, input().split()))

ts = set([i for i in range(N+1)])

last = 0
for m in range(M1):
    t = last + Am[m]
    last = t
    if t in ts:
        ts.remove(t)

last = N
for m in range(M2):
    t = last - Bm[m]
    last = t
    if t in ts:
        ts.remove(t)

print(len(ts))