#include<bits/stdc++.h>
using namespace std;
#define int long long
const int INF=0x3f3f3f3f3f;
queue<int> p[100020];
#define pii pair<int,int>
priority_queue<pii> q;
int a[100020],b[100020],vis[100010];
int cdian[100010][2];
inline void solve(){
	int num,m;
	cin>>num>>m;
	for(int i=1;i<=num;i++){
		//p[i].clear();
		cin>>a[i];
		vis[i]=0;
		b[i]=a[i];
	}
	while(q.size()){
		q.pop();
	}
	//q.clear();
	for(int i=1;i<=m;i++){
		int a,b;
		cin>>a>>b;
		cdian[i][1]=b,cdian[i][0]=a;
		p[b].push(a);
	}
	for(int i=1;i<=num;i++){
		if(p[i].size()){
			q.push({p[i].front()*(-1),i});
			p[i].pop();
		}
		else{
			vis[i]=-1;
			q.push({-INF,i});
		}
	}
	int cnt=0;
	for(int i=1;i<=m;i++){
		int x=cdian[i][0];
		while(q.size()){
			int jl=q.top().first*(-1),pos=q.top().second;//加油的距离、油的种类
			q.pop();
			if(jl<=cnt){
				continue;
			}
			if(cnt+a[pos]<x){
				cnt+=a[pos];
				a[pos]=0;	
			}
			else{
				a[pos]=a[pos]-(x-cnt);
				cnt=x;
				a[cdian[i][1]]=b[cdian[i][1]];
				if(p[cdian[i][1]].size()){
					q.push({p[cdian[i][1]].front()*(-1),cdian[i][1]});
					p[cdian[i][1]].pop();
				}
				else if(vis[cdian[i][1]]!=-1){
					vis[cdian[i][1]]=-1;
					q.push({-INF,cdian[i][1]});
				}
				break;
			}
		}
		//cout<<cnt<<endl;
	}
	for(int i=1;i<=num;i++){
		cnt+=a[i];
		//cout<<a[i]<<endl;
		while(p[i].size()){
			p[i].pop();
		}
	}
	cout<<cnt<<endl;
}
signed main(){
	ios::sync_with_stdio(false);
	cin.tie(0);
	int T;
	cin>>T;
	while(T--){
		solve();
	}
}