#include <bits/stdc++.h>
using namespace std;
const long long MOD = 1e9 + 7;
const long long N = 1e5 + 10;
const long long inf = 10000000;
inline bool EQ(double a, double b) { return fabs(a - b) < 1e-9; }
inline bool isLeapYear(long long year) {
  return (year % 400 == 0) || (year % 4 == 0 && year % 100 != 0);
}
inline void normal(long long& a) {
  a %= MOD;
  (a < 0) && (a += MOD);
}
inline long long modMul(long long a, long long b) {
  a %= MOD, b %= MOD;
  normal(a), normal(b);
  return (a * b) % MOD;
}
inline long long modAdd(long long a, long long b) {
  a %= MOD, b %= MOD;
  normal(a), normal(b);
  return (a + b) % MOD;
}
inline long long modSub(long long a, long long b) {
  a %= MOD, b %= MOD;
  normal(a), normal(b);
  a -= b;
  normal(a);
  return a;
}
inline long long modPow(long long b, long long p) {
  long long r = 1;
  while (p) {
    if (p & 1) r = modMul(r, b);
    b = modMul(b, b);
    p >>= 1;
  }
  return r;
}
inline long long modInverse(long long a) { return modPow(a, MOD - 2); }
inline long long modDiv(long long a, long long b) {
  return modMul(a, modInverse(b));
}
int dx[] = {0, 0, 1, -1};
int dy[] = {1, -1, 0, 0};
void dfs() {}
bool cmp() {}
bool solve(string s) {
  string x = s;
  reverse(x.begin(), x.end());
  return x == s;
}
clock_t b = clock();
string check() {
  clock_t e = clock();
  double t = (e - b) / CLOCKS_PER_SEC;
  return !(t <= (double)1e8) ? "FUCK" : "YAAAH";
}
long long f[N];
set<long long> st;
unordered_map<long long, long long> Mp;
int main() {
  memset(f, 0, sizeof f);
  ;
  long long n;
  scanf("%lld", &n);
  st.clear();
  while (n--) {
    long long x, y;
    scanf("%lld %lld", &x, &y);
    if (st.find(x) == st.end()) {
      st.insert(x);
      Mp[x] = y;
    } else
      Mp[x] = max(y, Mp[x]);
  }
  long long m;
  scanf("%lld", &m);
  while (m--) {
    long long x, y;
    scanf("%lld %lld", &x, &y);
    if (st.find(x) == st.end()) {
      st.insert(x);
      Mp[x] = y;
    } else
      Mp[x] = max(y, Mp[x]);
  }
  long long to = 0;
  for (auto it : st) to += Mp[it];
  cout << to << endl;
}
