#include <bits/stdc++.h>
using namespace std;
class Debugger {
 public:
  Debugger(const std::string& _separator = ", ")
      : first(true), separator(_separator) {}
  template <typename ObjectType>
  Debugger& operator,(const ObjectType& v) {
    if (!first) cerr << separator;
    cerr << v;
    first = false;
    return *this;
  }
  ~Debugger() { cerr << "\n"; }

 private:
  bool first;
  string separator;
};
template <typename T1, typename T2>
inline ostream& operator<<(std::ostream& os, const std::pair<T1, T2>& p) {
  return os << "(" << p.first << ", " << p.second << ")";
}
template <typename T>
inline ostream& operator<<(ostream& os, const vector<T>& v) {
  bool first = true;
  os << "[";
  for (unsigned long long i = 0; i < v.size(); i++) {
    if (!first) os << ", ";
    os << v[i];
    first = false;
  }
  return os << "]";
}
template <typename T>
inline ostream& operator<<(ostream& os, const set<T>& v) {
  bool first = true;
  os << "[";
  for (typename set<T>::const_iterator ii = v.begin(); ii != v.end(); ++ii) {
    if (!first) os << ", ";
    os << *ii;
    first = false;
  }
  return os << "]";
}
template <typename T1, typename T2>
inline ostream& operator<<(ostream& os, const map<T1, T2>& v) {
  bool first = true;
  os << "[";
  for (typename map<T1, T2>::const_iterator ii = v.begin(); ii != v.end();
       ++ii) {
    if (!first) os << ", ";
    os << *ii;
    first = false;
  }
  return os << "]";
}
long long n, m;
long long x, y;
long long xx, yy;
set<long long> elementi;
map<long long, long long> used;
int main() {
  ios_base::sync_with_stdio(0);
  ;
  cin >> n;
  for (long long i = 1; i <= n; i++) {
    cin >> x >> y;
    elementi.insert(x);
    used[x] = max(used[x], y);
  }
  cin >> m;
  for (long long i = 1; i <= m; i++) {
    cin >> x >> y;
    elementi.insert(x);
    used[x] = max(used[x], y);
  }
  long long cnt = 0;
  for (const auto& i : elementi) {
    cnt += used[i];
  }
  cout << cnt << "\n";
  return 0;
}
