#include <bits/stdc++.h>
#define int long long
#define io ios::sync_with_stdio(0),cin.tie(0),cout.tie(0)
#define pb push_back
using namespace std;
const int N=1e6+5,mod1=1e9+7,mod2=998244353,inf=1e18;
typedef pair<int,int> pi;
int a[N];
int x[N],y[N];
void solve()
{
    int n,m;
    cin>>n>>m;
    int ans=0;
    for(int i=1;i<=n;i++)
    {
        cin>>a[i];
        ans+=a[i];
    }
    //cout<<ans<<'\n';
    for(int i=1;i<=m;i++)cin>>x[i]>>y[i];
    int last=0;
    for(int i=1;i<=m;i++)
    {
        if(ans>=x[i])
        {
            if(y[i]==y[i-1])
            {
                ans+=min(a[y[i]],x[i]-x[i-1]);
                continue;
            }
            ans+=min(a[y[i]],x[i]-x[i-1]+last);
            last+=max(0ll,x[i]-x[i-1]-a[y[i]]);
        }
        else break;
    }
    cout<<ans<<'\n';
}
signed main()
{
    io;
    int t=1;
    cin>>t;
    while(t--)
    {
        solve();
    }
    return 0;
}