n = int(input())
m1 = int(input())
a = list(map(int, input().split()))
m2 = int(input())
b = list(map(int, input().split()))

dirty = set()

current = 0
dirty.add(current)
for num in a:
    current += num
    dirty.add(current)

sum_b = 0
for num in b:
    sum_b += num
    pos = n - sum_b
    dirty.add(pos)

print(n + 1 - len(dirty))