a=int(input())
b=int(input())
c=list(map(int, input().split()))
d=int(input())
e= list(map(int, input().split()))
f=[0]*(a+1)
g=0
for i in range(len(c)):
    g+=c[i]
    f[g]=1
g=a
for i in range(len(e)):
    g-=e[i]
    f[g]=1
g=0
for i in range(len(f)):
    if f[i]==0:
        g+=1
print(g)