#include <algorithm>
#include <bit>
#include <bitset>
#include <cassert>
#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <deque>
#include <iostream>
#include <map>
#include <random>
#include <unordered_set>
#include <unordered_map>
#include <vector>
#include <set>
#include <string>

using namespace::std;

template<typename T, typename U>
ostream& operator<< (ostream& o, const pair<T, U>& p) {
  o << "<" << p.first << ", " << p.second << ">";
  return o;
}

template <typename T>
ostream& operator<< (ostream& o, const vector<T>& v) {
 for (const auto& x : v) o << x << " ";
 return o;
}

template <typename T>
ostream& operator<< (ostream& o, const set<T>& v) {
 for (const auto& x : v) o << x << " ";
 return o;
}

template <typename T>
ostream& operator<< (ostream& o, const deque<T>& v) {
 for (const auto& x : v) o << x << " ";
 return o;
}

template <typename K, typename V>
ostream& operator<<(ostream& o, const unordered_map<K, V>& m) {
  o << "{";
  for (const auto& [k, v] : m)
    o << " " << k << ": " << v << ",";
  o << "}";
  return o;
}

template <typename T>
ostream& operator<< (ostream& o, const vector<vector<T>>& v) {
 for (const auto& x : v) o << x << endl;
 return o;
}

ostream& operator<< (ostream& o, const vector<string>& v) {
 for (const auto& x : v) o << x << endl;
 return o;
}



template <typename T>
istream& operator>> (istream& i, vector<T>& v) {
  for (auto& x : v) i >> x;
  return i;
}

istream& operator>> (istream& i, pair<int, int>& p) {
  i >> p.first >> p.second;
  return i;
}



int main() {
  ios::sync_with_stdio(false);
  long long n, m1;
  cin >> n >> m1;
  long long c = 0;
  unordered_set<long long> v {0};
  for (int i = 0; i < m1; ++i) {
    int a;
    cin >> a;
    c += a;
    v.insert(c);
  }
  int m2;
  cin >> m2;
  c = n;
  v.insert(n);
  for (int i = 0; i < m2; ++i) {
    int b;
    cin >> b;
    c -= b;
    v.insert(c);
  }
  cout << n + 1 - v.size() << endl;
  

  return 0;
}