def main():
    n = int(input())
    m1 = int(input())
    a = list(map(int,input().split()))
    m2 = int(input())
    b = list(map(int,input().split()))
    is_dirty = [False] * (n+1)
    here = 0
    is_dirty[here] = True
    for i in range(m1):
        here += a[i]
        is_dirty[here] = True

    for i in range(m2):
        here -= b[i]
        is_dirty[here] = True

    print((n+1) - is_dirty.count(True))


if __name__ == '__main__':
    main()