#include <bits/stdc++.h>

using i64 = long long;
using A2 = std::array<i64, 2>;

#define Fast_IOS \
	std::ios::sync_with_stdio(false), \
	std::cin.tie(0), \
	std::cout.tie(0)

const i64 mod = 998244353;

int N, T = 1;

void init() {
	Fast_IOS;
	std::cin >> T;
}

void solve() {
	i64 n, m;
	std::cin >> n >> m;
	std::vector<i64> a(n + 1);
	i64 sum = 0;
	for (int i = 1; i <= n; i++) {
		std::cin >> a[i];
		sum += a[i];
	}
	std::vector<A2> chg(m + 1);
	for (int i = 1; i <= m; i++) {
		i64 x, t;
		std::cin >> x >> t;
		chg[i] = {x, a[t]};
	}
	i64 fuel = sum, cost = 0;
	for (int i = 1; i <= m; i++) {
		cost += chg[i][0] - chg[i - 1][0];
		if (cost > sum) {
			std::cout << fuel << '\n';
			return;
		}
		i64 t = std::min(cost, chg[i][1]);
		fuel += t;
		cost -= t;
	}
	std::cout << fuel << '\n';
}

int main() {
	init();
	while (T--) {
		solve();
	}
	return 0;
}