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

seen = [True] * (N+1)
up = 0
seen[up] = False
for i in range(M1):
    up += A[i]
    seen[up] = False
down = N
seen[down] = False
for i in range(M2):
    down -= B[i]
    seen[down] = False
print(sum(seen))