n = int(input())
m1 = int(input())
a = list(map(int, input().split()))
m2 = int(input())
b = list(map(int, input().split()))
st = {0, n}

s = 0
for i in range(m1):
	s += a[i]
	st.add(s)
s = 0
for i in range(m2):
	s += b[i]
	st.add(s)
	
print(n + 1 - len(st))