#define _USE_MATH_DEFINES
#include <algorithm>
#include <cstdio>
#include <functional>
#include <iostream>
#include <cfloat>
#include <climits>
#include <cstring>
#include <cmath>
#include <map>
#include <queue>
#include <random>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <time.h>
#include <vector>
using namespace std;

typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> i_i;
typedef pair<ll, int> ll_i;
typedef pair<double, int> d_i;
typedef pair<ll, ll> ll_ll;
typedef pair<double, double> d_d;
struct edge { int u, v, y, m; };

ll MOD = 1000000007;
ll _MOD = 1000000009;
double EPS = 1e-10;

int f(int N, vector<int>& a, vector<int>& B, vector<int>& C) {
	int sum = 0;
	for (int i = 0; i < N; i++)
		if (a[i] == 1) sum += C[i];
		else if (a[i] == 2) sum += B[i];
	return sum;
}

int main() {
	int N; cin >> N;
	vector<int> B(N), C(N);
	for (int i = 0; i < N; i++)
		cin >> B[i] >> C[i];
	int M; cin >> M;
	vector<i_i> p(M);
	for (int j = 0; j < M; j++)
		cin >> p[j].first >> p[j].second;
	sort(p.begin(), p.end());
	vector<int> D(M), E(M);
	for (int j = 0; j < M; j++) {
		D[j] = p[j].first;
		E[j] = p[j].second;
	}
	vector<int> a(N);
	random_device rd;
	mt19937 mt(rd());
	int ans = 0;
	for (int x = 0; x < 59049; x++) {
		int y = x;
		for (int i = 0; i < min(10, N); i++) {
			a[i] = y % 3;
			y /= 3;
		}
		int z = 0, maxi = 0;
		for (int t = 99; t >= 0; t--) {
			vector<int> _a = a;
			if (N > 10) {
				int i = 10 + mt() % (N - 10);
				if (mt() % 2) _a[i] = (_a[i] + 1) % 3;
				else _a[i] = (_a[i] + 4) % 3;
			}
			for (int j = 0; j < M; j++)
				if (_a[D[j]] == 2 && _a[E[j]] == 1)
					_a[E[j]] = 2;
			int _z = f(N, _a, B, C);
			if (_z > x - t / 10) {
				z = _z;
				a = _a;
			}
			maxi = max(maxi, z);
		}
		ans = max(ans, maxi);
	}
	cout << ans << endl;
}