#include <bits/stdc++.h>

using namespace std;

int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int n;
  cin >> n;
  int m1;
  cin >> m1;
  vector<int> up(m1);
  for (int i=0;i<m1;++i) cin >> up[i];
  int m2;
  cin >> m2;
  vector<int> down(m2);
  for (int i=0;i<m2;++i) cin >> down[i];

  vector<int> a(n+1, 0);
  int now {0};
  a[now] = 1;
  for (int i=0;i<m1;++i) {
    now += up[i];
    a[now] = 1;
  }
  for (int i=0;i<m2;++i) {
    now -= down[i];
    a[now] = 1;
  }

  int ans {};
  for (int i=0;i<=n;++i) if (a[i] == 0) ++ans;
  cout << ans << '\n';
}