#include <bits/stdc++.h>
using namespace std;
template <class T1>
void deb(T1 e1) {
  cout << e1 << endl;
}
template <class T1, class T2>
void deb(T1 e1, T2 e2) {
  cout << e1 << " " << e2 << endl;
}
template <class T1, class T2, class T3>
void deb(T1 e1, T2 e2, T3 e3) {
  cout << e1 << " " << e2 << " " << e3 << endl;
}
template <class T1, class T2, class T3, class T4>
void deb(T1 e1, T2 e2, T3 e3, T4 e4) {
  cout << e1 << " " << e2 << " " << e3 << " " << e4 << endl;
}
template <class T1, class T2, class T3, class T4, class T5>
void deb(T1 e1, T2 e2, T3 e3, T4 e4, T5 e5) {
  cout << e1 << " " << e2 << " " << e3 << " " << e4 << " " << e5 << endl;
}
template <class T1, class T2, class T3, class T4, class T5, class T6>
void deb(T1 e1, T2 e2, T3 e3, T4 e4, T5 e5, T6 e6) {
  cout << e1 << " " << e2 << " " << e3 << " " << e4 << " " << e5 << " " << e6
       << endl;
}
int main() {
  int n, m;
  while (scanf("%d", &n) == 1) {
    int i, j, k;
    map<int, int> mp1;
    long long sum = 0;
    for (i = 0; i < n; i++) {
      int a, b;
      scanf("%d%d", &a, &b);
      sum += b;
      mp1[a] = b;
    }
    scanf("%d", &m);
    for (i = 0; i < m; i++) {
      int a, b;
      scanf("%d%d", &a, &b);
      if (mp1[a]) {
        sum -= mp1[a];
        sum += (max(b, mp1[a]));
      } else
        sum += b;
    }
    deb(sum);
  }
}
