#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 x = 0, maxi = 0;
	for (int t = 0; t < 1000000; t++) {
		vector<int> _a = a;
		int i = t % N; //mt() % N;
		if (mt() % 2) _a[i] = (_a[i] + 1) % 3;
		else _a[i] = (_a[i] - 1) % 3;
		for (int j = 0; j < M; j++)
			if (_a[D[j]] == 2 && _a[E[j]] == 1)
				_a[E[j]] = 2;
		int _x = f(N, _a, B, C);
		if (_x > x - (1000000 - t) / 1000) {
			x = _x;
			a = _a;
		}
		maxi = max(maxi, x);
	}
	cout << maxi << endl;
}