#include <iostream>
#include <vector>

using namespace std;
using ll = long long;

int main() {
  ll n;
  cin >> n;
  vector<bool> foot(n);
  ll m;
  cin >> m;
  ll now = 0;
  for (ll i = 0; i < m; i++) {
    ll a;
    cin >> a;
    foot[now] = true;
    now += a;
  }

  cin >> m;
  for (ll i = 0; i < m; i++) {
    ll b;
    cin >> b;
    now -= b;
    foot[now] = true;
  }

  ll ans = 0;
  for (ll i = 0; i < n; i++)
    ans += !foot[i];
  cout << ans << "\n";
}