#include <bits/stdc++.h>
using namespace std;
#ifdef LOCAL
  #include "settings/debug.cpp"
  #define _GLIBCXX_DEBUG
#else
  #define Debug(...) void(0)
#endif
#define rep(i, n) for (int i = 0; i < (n); ++i)
using ll = long long;
using ull = unsigned long long;

int main() {
  int n;
  cin >> n;
  vector<bool> dirty(n + 1, false);
  dirty[0] = dirty[n] = true;
  int m;
  cin >> m;
  int now = 0;
  rep(i, m) {
    int a;
    cin >> a;
    now += a;
    dirty[now] = true;
  }
  cin >> m;
  assert(now == n);
  rep(i, m) {
    int a;
    cin >> a;
    now -= a;
    dirty[now] = true;
  }
  int ans = 0;
  rep(i, n + 1) {
    if (!dirty[i]) ans++;
  }
  cout << ans << endl;
  return 0;
}