#include <bits/stdc++.h>
using namespace std;
template <class L, class R>
ostream &operator<<(ostream &os, pair<L, R> P) {
  return os << "(" << P.first << "," << P.second << ")";
}
template <class T>
ostream &operator<<(ostream &os, vector<T> V) {
  os << "[";
  for (auto vv : V) os << vv << ",";
  return os << "]";
}
template <class L, class R>
ostream &operator<<(ostream &os, map<L, R> M) {
  os << "[";
  for (auto pr : M) os << pr.first << "->" << pr.second << ",";
  return os << "]";
}
template <class L, class R>
ostream &operator<<(ostream &os, unordered_map<L, R> M) {
  os << "[";
  for (auto pr : M) os << pr.first << "->" << pr.second << ",";
  return os << "]";
}
mt19937_64 mt(time(0));
struct Matrix {
  vector<vector<int>> data;
  int r, c;
  Matrix(int row, int col, bool identity = false) : r(row), c(col) {
    data.assign(row, vector<int>(col, 0));
    if (identity) {
      for (int i = 0; i < r; ++i) {
        data[i][i] = 1;
      }
    }
  }
  Matrix operator*(Matrix &other) {
    int m = r, n = c, p = other.c;
    Matrix res(m, p);
    for (int i = 0; i < m; ++i) {
      for (int j = 0; j < p; ++j) {
        for (int k = 0; k < n; ++k) {
          res.data[i][j] += data[i][k] * other.data[k][j];
        }
      }
    }
    return res;
  }
};
vector<int> extendGcd(int a, int b) {
  if (b == 0) {
    return {1, 0, a};
  } else {
    vector<int> tmp = extendGcd(b, a % b);
    return {tmp[1], tmp[0] - (a / b) * tmp[1], tmp[2]};
  }
}
Matrix matrix_power(Matrix base, long long exp) {
  int n = base.r;
  Matrix res(n, n, true);
  while (exp) {
    if (exp & 1) {
      res = res * base;
    }
    base = base * base;
    exp >>= 1;
  }
  return res;
}
map<int, int> dp;
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  cout.precision(10);
  cout << fixed;
  int n;
  int u, v;
  cin >> n;
  for (int i = 1; i <= n; ++i) {
    cin >> u >> v;
    dp[u] = max(dp[u], v);
  }
  int m;
  cin >> m;
  for (int i = 1; i <= m; ++i) {
    cin >> u >> v;
    dp[u] = max(dp[u], v);
  }
  long long res = 0;
  for (auto pr : dp) res += pr.second;
  cout << res;
  return 0;
}
