#include <iostream>
#include <algorithm>
#define x first
#define y second
using namespace std;

typedef long long LL;
typedef pair<int,int> PII; 
const int N=100010;
int n,m;
int a[N],c[N];
PII b[N];

int main() {
	int T;
	cin>>T;
	while(T--){
		cin>>n>>m;
		LL sum=0,now=0;
		for(int i=1;i<=n;++i){
			cin>>a[i];
			sum+=a[i];
			c[i]=a[i];
		}
		for(int i=1;i<=m;++i){
			cin>>b[i].x>>b[i].y;
		}
		for(int i=1;i<=m;++i){
			int j=i;
			while(j<=m&&now<b[i].x){
				int t=min(b[i].x-now,(LL)c[b[j].y]);
				now+=t;
				c[b[j].y]-=t;
				++j;
			}
			sum+=(a[b[i].y]-c[b[i].y]);
			c[b[i].y]=a[b[i].y];
		}
		cout<<sum<<endl;
	}
	return 0;
}