#include <bits/stdc++.h>
using namespace std;
const long long N = 3e5 + 20, M = 998244353;
#define eps 1e-12
#define int long long
// #define int __int128
#define ll long long
#define all(x) x.begin(), x.end()
#define endl '\n'
#define ls (p << 1)
#define rs ((p << 1) | 1)
#define f1 first
#define pb push_back
#define f2 second
#define IOS ios::sync_with_stdio(0), cin.tie(0), cout.tie(0), cout << fixed << setprecision(2);
int t, n, m, a[N], x[N], tr[N];
int b[N], x2[N], x3[N];
set<int> st[N];
signed main()
{
	IOS;
	cin >> t;
	while (t--)
	{
		cin >> n >> m;
		for (int i = 1; i <= n; i++)
			cin >> a[i], b[i] = a[i], st[i].clear();
		for (int i = 1; i <= m; i++)
			cin >> x[i] >> tr[i], x2[i] = x[i] - x[i - 1], x3[i] = x[i], st[i].insert(i);
		for (int i = 1; i <= m; i++)
			x[i] = x2[i];
		int ans = 0;
		struct g
		{
			int i, id;
			bool operator<(const g b) const
			{
				return i > b.i;
			}
		};
		priority_queue<g> Q;
		queue<int> q;
		for (int i = 1; i <= n; i++)
			q.push(i);
		for (int i = 1; i <= m; i++)
		{
			Q.push({i, tr[i]});
		}
		for (int i = 1; i <= m; i++)
		{
			while (Q.size() && x[i])
			{
				auto [j, id] = Q.top();
				Q.pop();
				if (j < i)
					continue;
				if (b[id] >= x[i])
				{
					b[id] -= x[i];
					x[i] = 0;
				}
				else
				{
					x[i] -= b[id];
					b[id] = 0;
				}
			}
			if (x[i] && !Q.size())
			{
				while (q.size() && x[i])
				{
					int p = q.front();
					q.pop();
					if (b[p] >= x[i])
					{
						b[p] -= x[i], x[i] = 0;
						q.push(p);
					}
					else
					{
						x[i] -= b[p], b[p] = 0;
					}
				}
				if (!q.size() && x[i])
				{
					ans = x3[i] - x[i];
					goto u;
				}
			}
			b[tr[i]] = a[tr[i]];
			q.push(tr[i]);
			auto u = st[tr[i]].lower_bound(i);
			if (u != st[tr[i]].end())
			{
				Q.push({*u, tr[i]});
			}
		}
		ans = x3[m];
	u:;
		for (int i = 1; i <= n; i++)
			ans += b[i];
		cout << ans << endl;
	}
	return false;
}