import itertools

N = int(input())
M1 = int(input())
A = [int(x) for x in input().split()]
M2 = int(input())
B = [int(x) for x in input().split()]
clean = set(range(N))
for i in itertools.accumulate(A):
  clean.discard(i)
for i in itertools.accumulate(B):
  clean.discard(N - i)
print(len(clean))