#include<bits/stdc++.h>
#define pii pair<int,int>
using namespace std;
int main()
{
	ios::sync_with_stdio(false);
	cin.tie(0);
	cout.tie(0);
	int T;
	cin>>T;
	while (T--)
	{
		int n,m;
		cin>>n>>m;
		vector<int>a(n+5),b(n+5),cnt(n+5);
		vector<int>nxt(m+5,m+1),id(n+5);
		vector<pii>x(m+5);
		stack<int>s;
		long long sum=0;
		for (int i=1;i<=n;++i) cin>>a[i],b[i]=a[i];
		for (int i=1;i<=m;++i) cin>>x[i].first>>x[i].second,cnt[x[i].second]++,nxt[id[x[i].second]]=i,id[x[i].second]=i;
		for (int i=m;i>=1;--i) s.push(i);
		for (int i=1;i<=n;++i) 
			if (!cnt[i]) sum+=a[i];
		int d=0;
		for (int i=1;i<=m;++i)
		{
			while (s.size()&&a[x[s.top()].second]<=x[i].first-d)
			{
				d+=a[x[s.top()].second];
				a[x[s.top()].second]=0;
				s.pop();
			}
			if (!s.size()) 
			{
				if (d+sum<x[i].first) {d+=sum;sum=0;break;}
				else sum-=x[i].first-d,d=x[i].first;
			}
			if (d!=x[i].first)
			{
				a[x[s.top()].second]-=x[i].first-d;
				d=x[i].first;
			}
			a[x[i].second]=b[x[i].second];
			if (!s.size()||nxt[i]<s.top()) s.push(nxt[i]);
			cnt[x[i].second]--;
			if (!cnt[x[i].second]) sum+=a[x[i].second];
		}
		d+=sum;
		cout<<d<<"\n";
	}
}