#include <bits/stdc++.h>
using namespace std;

#define int long long

const int N = 2e5 + 10;

void solve()
{

	int n, m;
	cin >> n >> m;
    int sum=0;
	vector<int> a(n + 5);
	vector<int> ini(n+5);
	vector<pair<int, int>> c(m + 5);
	for (int i = 1; i <= n; i++)
	{
		cin >> a[i];
		ini[i]=a[i];
        sum+=a[i];
	}
    int p=0;
	for (int i = 1; i <= m; i++)
	{
		int u, v;
		cin >> u >> v;
		c[i].first = u;
		c[i].second = v;
	}
	int res = 0;
	int l = 1;
	int r = 1;
	for (int i = 1; i <= m; i++)
	{
		if(sum<c[i].first)break;
        sum+=min(a[c[i].second],c[i].first-p);
        p=min(p+a[c[i].second],c[i].first);
        
		
	}
	cout<<sum<<endl;
}

signed main()
{
	ios::sync_with_stdio(0);
	cin.tie(0), cout.tie(0);

	int t = 1;
	cin >> t;
	while (t--)
	{
		solve();
	}

	return 0;
}