#include<bits/stdc++.h>
using namespace std;
#define int long long
typedef pair<int,int> PII;
#define endl "\n"
#define ft first
#define sd second
#define pb push_back
const int MOD = 1e9 + 7;
int n,m;
const int N = 1e5 + 10;
int a[N],c[N];
struct node{
    int dis,id;
}b[N];
void solve() {
    cin>>n>>m;
    int sum = 0;
    for(int i = 1;i <= n;i++) {
        cin>>a[i];
        sum +=a[i];
        c[i] = a[i];
    }
//    cout<<sum<<endl;
    queue<node> q;
    map<int,int> mp;
    for(int i = 1;i <= m;i++){
        int x,y; cin>>x>>y;
        b[i] = {x,y};
        mp[x] = 1;
        q.push({x,y});
    }
    queue<int> q1;
    for(int i = 1;i <= n;i++){
        if(!mp.count(i)) q1.push(i);
    }
    b[0] = {0,0};
    int now = 0;
    for(int i = 1;i <= m;i++){
        int d = b[i].dis - b[i - 1].dis;
        if(sum >= d){
            sum -=d;
            // charge out
            while(d && q.size()){
                auto t = q.front(); q.pop();
                int dx = a[t.id];
                if(dx <= d) {
                    d-=dx;
                    a[t.id] = 0;
                }
                else {
                    dx -=d;
                    d = 0;
                    a[t.id] = dx;
//                    cout<<t.id<<' '<<dx<<' '<<endl;
//                    system("pause");
                }
            }
            while(d && q1.size()){
                int t = q1.front(); q1.pop();
                if(d >= a[t]){
                    d -=a[t];
                    a[t] = 0;
                }
                else {
                    a[t]-=d;
                    d = 0;
                }
            }
//            cout<<"begin = "<<endl;
//            for(int i = 1;i <= n;i++)
//                cout<<a[i]<<' ';
//            cout<<endl;
            int dx = c[b[i].id] - a[b[i].id];
            a[b[i].id] = c[b[i].id];
            sum +=dx;
            now +=b[i].dis - b[i - 1].dis;
//            cout<<sum<<' '<<now<<endl;
//            cout<<"end = "<<endl;
//            for(int i = 1;i <= n;i++)
//                cout<<a[i]<<' ';
//            cout<<endl;
        }
        else break;
    }
//    cout<<now<<' '<<sum<<' '<<endl;
    now +=sum;
    cout<<now<<endl;
    return ;
}
signed main() {
//    ios::sync_with_stdio(0);
//    cin.tie(0);
//    cout.tie(0);
    int T = 1;
    cin>>T;
    while(T--)
        solve();
    return 0;
}
/*
2
3 1
3 3 3
8 1
2 2
5 2
1 2
2 1

 */