from collections import *
import heapq
import bisect
import itertools


INF = float("inf")
MOD = 998244353
mod = 998244353

N = int(input())
now = 0
dirty = [0] * (N + 1)
M = int(input())
A = list(map(int, input().split()))
for a in A:
    now += a
    dirty[now] = 1

now = N
M = int(input())
A = list(map(int, input().split()))
for a in A:
    now -= a
    dirty[now] = 1

print(dirty[1:].count(0))