#include <iostream>
#include <cstdio>
#include <cctype>
#define il inline
#define ll long long
#define int long long
#define gc getchar
using namespace std;
il int read() {
	int x=0;bool f=0;char ch=gc();
	while(!isdigit(ch)) {f|=ch=='-';ch=gc();}
	while(isdigit(ch)) {x=(x<<1)+(x<<3)+(ch^48);ch=gc();}
	return f?-x:x;
}	

const int N=1e5+10;
int T,n,m;
int a[N];
int x[N],t[N];

signed main() {
	T=read();
	while(T--) {
		n=read();m=read();
		int sum=0;
		int now=0;
		for(int i=1;i<=n;++i) {
			a[i]=read();
			sum+=a[i];
		}	
		now=sum;
		for(int i=1;i<=m;++i) {
			x[i]=read();t[i]=read();
		}	
		int xb=0;
		for(int i=1;i<=m;++i) {
			if(now>=x[i]-x[i-1]) {
				now-=(x[i]-x[i-1]);
				xb=i;
				now+=a[t[i]];
				now=min(now,sum);
			}	
			else break;
		}	
		printf("%lld\n",x[xb]+now);
	}	
	return 0;
}