import itertools

n = int(input())
m_1 = int(input())
A = list(map(int, input().split()))
m_2 = int(input())
B = list(map(int, input().split()))

A_ = list(itertools.accumulate(A))
B_ = []

tmp = n
for x in B:
  tmp -= x
  B_.append(tmp)

# print(A_)
# print(B_)

  

  

num_set = set(range(n + 1))
for xx in A_:
  num_set.discard(xx)

for yy in B_:
  num_set.discard(yy)

print(len(num_set))