#include <bits/stdc++.h>
#define MAX 0x3f3f3f3f
#define endl "\n"
using namespace std;
using ll = long long;
// struct node{
// 	int p,x;
// };
void solve(){
	int n,m;
	cin>>n>>m;
	vector <ll> a(n+1);
	ll sum=0;
	for(int i=1;i<=n;i++){
		cin>>a[i];
		sum+=a[i];
	}
	// priority_queue <node> w;
	// priority_queue <node> v;
	vector <ll> x(m+1);
	vector <ll> t(m+1);
	for(int i=1;i<=m;i++){
		cin>>x[i]>>t[i];
	}
	ll w=0;
	ll ans=0;
	for(int i=1;i<=m;i++){
		w=x[i]-x[i-1];
		if(sum<w){
			cout<<ans+sum<<endl;
			return;
		}
		sum-=w;
		ans+=w;
		sum+=min(w,a[t[i]]);
	}
	cout<<ans+sum<<endl;
}
int main(){
	ios::sync_with_stdio(false);
	cin.tie(0);
	cout.tie(0);
	//solve();
	ll t;
	cin>>t;
	while(t--){
		solve();
	}
	return 0;
}