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

signed main()
{
    int t;
    cin >> t;
    while (t--)
        solve();

    return 0;
}