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

visited=[False]*(n+1)
now=0
visited[now]=True
for ai in a:
	now+=ai
	visited[now]=True

for bi in b:
	now-=bi
	visited[now]=True

print(n+1-sum(visited))