// Problem: A - New Energy Vehicle
// Contest: Virtual Judge - 思维
// URL: https://vjudge.net/contest/670080#problem/A
// Memory Limit: 1024 MB
// Time Limit: 2000 ms
// 
// Powered by CP Editor (https://cpeditor.org)

#include<bits/stdc++.h>
#define int long long
#define fi first
#define se second
#define PII pair<int, int>

using namespace std;

const int N = 2e5 + 10, M = 1e6 + 10, mod = 1e9 + 7, INF = 0x3f3f3f3f;

int n, m, q, ans;
int s[N], dp[N], cy[N];
bool vis[N];
PII p[N];

vector<int> e[N];

signed main()
{
	ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);
	int T; cin >> T;
	while(T --)
	{
		vector<PII> pq;
		cin >> n >> m; int sum = 0, tag = 0; bool flag = false;
		// for(int i = 1; i <= n; i ++) vis[i] = false;
		for(int i = 1; i <= n; i ++) {cin >> s[i]; cy[i] = s[i];}
		for(int i = 1; i <= m; i ++) {cin >> p[i].fi >> p[i].se; pq.push_back({p[i]});}
		for(int i = 1; i <= n; i ++) pq.push_back({INF, i});
		for(int i = 1; i <= m; i ++)
		{
			int dis = p[i].fi - p[i - 1].fi;
			for(auto j : pq)
			{
				if(j.fi < p[i].fi || !s[j.se]) continue;
				// cout << "dis = " << dis << " now = " << now << " left = " << s[now] << '\n';
				if(s[j.se] > dis) 
				{
					s[j.se] -= dis, dis = 0;
					break;
				}
				else dis -= s[j.se], s[j.se] = 0; 		
			}
			// cout << "dis = " << dis << '\n';
			if(dis) 
			{
				for(int j = 1; j <= n; j ++) 
				{
					if(s[j] > dis) s[j] -= dis, dis = 0;
					else dis -= s[j], s[j] = 0; 		
				}
				if(dis) 
				{
					cout << p[i].fi - dis << '\n'; 
					flag = true; 
					break;
				}
			}
			s[p[i].se] = cy[p[i].se]; pq.push_back({INF, p[i].se});
		}
		if(flag) continue;
		for(int i = 1; i <= n; i ++) sum += s[i];
		cout << p[m].fi + sum << '\n';
		// if(!flag) cout << p[m].fi + (sum - tag) << '\n';
	}	
	return 0;
}