#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int N = 2e5+5;
ll a[N];
ll p[N];
void solve()
{
    int n,m;
    cin>>n>>m;
    ll sum = 0;
    for(int i=1;i<=n;i++){
        cin>>a[i];
        sum += a[i];
        p[i] = 0;
    }
    ll len = 0;
    ll x,y;
    for(int i=1;i<=m;i++){
        cin>>x>>y;
        if(x-len>sum){
            cout<<len+sum<<'\n';
            return ;
        }
        ll acm = a[y] - x + p[y];
        if(acm<0)acm = 0;
        ll res = x - len - acm;
        if(res>0){
            sum-=res;
            sum+=a[y];
        }
        //sum+=a[y];
        p[y] = x;
        len = x;
    }
    cout<<x+sum<<"\n";
    return ;
}

int main()
{
    cin.tie(0)->ios::sync_with_stdio(false);

    int t = 1;
    cin >> t;
    while (t--)
        solve();

    return 0;
}