N = int(input())
M = int(input())
A = list(map(int, input().split()))
M = int(input())
B = list(map(int, input().split()))
S = set()
step = 0
for a in A:
    step+=a
    S.add(step)
for b in B:
    step-=b
    S.add(step)
print(N-len(S)+1)