#include <cstdio>
#include <iostream>
#include <algorithm>
#include <cstring>
#include <string>
#include <map>
#include <queue>
#include <bitset>
#include <vector>
#include <stack>
#include <cmath>
#include <set>
#include <cassert>
#include <random>
#include <chrono>
#include <ctime>
#include <cstdlib>
#define pii pair<int,int> 
#define mp make_pair
#define pb emplace_back
#define debug() cout<<"qwq"<<endl
typedef long long ll;
typedef double db;
typedef long double ldb;
typedef unsigned long long ull;
const int DMAX = 200000 + 5;
const double INF = 1e9;
const int MOD = 998244353;
using namespace std;
mt19937 rnd(chrono::steady_clock::now().time_since_epoch().count());
template<class T> inline void read(T &x){
	T f=1; x=0; char ch=getchar();
	while(ch<'0' || ch>'9'){
		if(ch=='-') f=-1; 
		ch=getchar();
	}
	while(ch<='9' && ch>='0'){ x=x*10+ch-'0';ch=getchar(); }
	x*=f;
}
int T;
int a[DMAX], real[DMAX];
int n, m;
int x[DMAX], t[DMAX];
int b[DMAX], cnt;
int las[DMAX];
void solve(){
	cnt = 0;
	read(n), read(m);
	for(int i = 1; i <= n; i++) read(a[i]), real[i] = a[i], las[i] = -1;
	for(int i = 1; i <= m; i++) read(x[i]), read(t[i]), b[++ cnt] = t[i], las[t[i]] = i;
	for(int i = 1; i <= n; i++) if(las[i] == -1) b[++ cnt] = i, las[i] = cnt; 
	ll now = 0;
	int p = 1;
	bool flag = 1;
	for(int i = 1; i <= m; i++){
		ll diff = x[i] - now;
		while(p <= cnt){
			if(diff > real[b[p]]){
				diff -= real[b[p]];
				now += real[b[p]];
				real[b[p]] = 0;
				p ++;
			}
			else{
				real[b[p]] -= diff;
				now += diff;
				diff = 0;
				break;
			}
		} 
		if(diff){
			flag = 0;
			break;
		}
		real[t[i]] = a[t[i]];
		if(las[t[i]] < p){
			b[++ cnt] = t[i], las[t[i]] = cnt; 
		}
		if(p == i){
			p ++;
		}
	}
	if(!flag){
		printf("%lld\n", now);
		return ;
	}
	//cout<<now<<endl;
	for(int i = 1; i <= n; i++){
		now += real[i];
	}
	printf("%lld\n", now);
	return ;
}
int main(){
	read(T);
	while(T --){
		solve();
	}
	return 0;
}