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

ans = [0] * (N + 1)
ans[0] = ans[-1] = 1
now = 0
for i in range(M1):
    now += A[i]
    ans[now] = 1
    
now = N
for i in range(M2):
    now -= B[i]
    ans[now] = 1
    
print(N + 1 - sum(ans))