#include <bits/stdc++.h>
using namespace std;
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  int n;
  cin >> n;
  map<int, int> mp1, mp2;
  map<int, int>::iterator it;
  for (int i = 0; i < n; i++) {
    int a, b;
    cin >> a >> b;
    mp1[a] = b;
  }
  int m;
  cin >> m;
  for (int i = 0; i < m; i++) {
    int a, b;
    cin >> a >> b;
    if (mp1.find(a) != mp1.end()) {
      it = mp1.find(a);
      if (it->second > b) {
        continue;
      } else {
        mp1.erase(it);
        mp2[a] = b;
      }
    } else {
      mp2[a] = b;
    }
  }
  long long sum = 0;
  it = mp1.begin();
  while (it != mp1.end()) {
    sum += it->second;
    it++;
  }
  it = mp2.begin();
  while (it != mp2.end()) {
    sum += it->second;
    it++;
  }
  cout << sum << "\n";
  return 0;
}
