/* -*- coding: utf-8 -*-
 *
 * 2401.cc:  No.2401 Dirty Shoes and Stairs - yukicoder
 */

#include<cstdio>
#include<algorithm>

using namespace std;

/* constant */

const int MAX_N = 200000;

/* typedef */

/* global variables */

int as[MAX_N], bs[MAX_N];
bool fs[MAX_N + 1];

/* subroutines */

/* main */

int main() {
  int n, m1, m2;
  scanf("%d", &n);
  scanf("%d", &m1);
  for (int i = 0; i < m1; i++) scanf("%d", as + i);
  scanf("%d", &m2);
  for (int i = 0; i < m2; i++) scanf("%d", bs + i);

  fs[0] = fs[n] = true;
  for (int i = 0, s = 0; i < m1; i++)
    s += as[i], fs[s] = true;
  for (int i = 0, s = n; i < m2; i++)
    s -= bs[i], fs[s] = true;

  int cnt = 0;
  for (int i = 0; i <= n; i++)
    if (! fs[i]) cnt++;

  printf("%d\n", cnt);
  return 0;
}