#include <bits/stdc++.h>
using namespace std;
#define db(x) cerr<<#x<<(x)<<"\n"
#define db1(x) cerr<<#x<<(x)<<" "
#define rep(i,a,b) for(auto i=(a);i<=(b);i++)
#define ll long long
const int N = 1e5+10;
int n,m;
ll x[N],id[N],a[N],na[N];
void solve(){
    ll sum=0;
    cin>>n>>m;
    for(int i=1;i<=n;i++){
        cin>>a[i];
        sum+=a[i];
    }
    ll ans=sum;
    x[0]=0;
    for(int i=1;i<=m;i++){
        cin>>x[i]>>id[i];
    }
    ll cnt=0;
    for(int i=1;i<=m;i++){
        if(sum>=x[i]-x[i-1]){
            sum-=x[i]-x[i-1];
            cnt+=x[i]-x[i-1];
            if(cnt>=a[id[i]]){
                sum+=a[id[i]];
                ans+=a[id[i]];
                cnt-=a[id[i]];
            }
            else{
                sum+=cnt;
                ans+=cnt;
                cnt=0;
            }
        }
        else break;
        //cout<<ans<<'\n';
    }
    cout<<ans<<'\n';
}
int main()
{
    ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
    int _ ;cin>>_;while(_--)solve();
}