#define _CRT_SECURE_NO_WARNINGS 1
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const ll MAX = 0x3f3f3f3f;
const ll mod = 998244353;
const ll N = 2e5 + 10;


ll a[N] = {}, x[N] = {}, t[N] = {};
void solve() {
	ll sum = 0;
	ll n, m; cin >> n >> m;
	for (int i = 1; i <= n; i++) {
		cin >> a[i]; sum += a[i];
	}
	ll tot = sum;
	for (int i = 1; i <= m; i++) cin >> x[i] >> t[i];
	for (int i = 1; i <= m; i++) {
		int dis = x[i] - x[i - 1];
		if (dis <= a[t[i]] && dis <= sum) {
			sum -= dis;
			sum += min(tot - sum, a[t[i]]);
		}
		else if (dis > a[t[i]] && dis <= sum) {
			sum -= dis - a[t[i]];
		}
		else if (dis > sum) {
			cout << x[i - 1] + sum;
			return;
		}
	}
	cout << x[m] + sum << endl;
}
int main() {
	ios::sync_with_stdio(0);
	cin.tie(0); cout.tie(0);
	int t = 1;
	cin >> t;
	while (t--)
		solve();
	return 0;
}