#include<bits/stdc++.h>
#define int long long
#define fi first
#define sd second
using namespace std;
const int N=5e5+5,inf=1e18;
inline int read(){
    int x;
    scanf("%lld",&x);
    return x;
}
int T,n,m,a[N],x[N],t[N],b[N];
bool vis[N];

/*
1
2 2
5 2
1 2
2 1
*/

signed main(){
    T=read();
    while(T--){
        n=read(),m=read();
        for(int i=1;i<=n;i++) b[i]=a[i]=read();
        priority_queue<pair<int,int>,vector<pair<int,int> >,greater<pair<int,int> > > q,qq;
        for(int i=1;i<=m;i++){
            x[i]=read(),t[i]=read();
            vis[t[i]]=1;
            q.push({x[i],t[i]});
            qq.push({x[i],t[i]});
        }
        for(int i=1;i<=n;i++) if(!vis[i]) q.push({inf,i}),qq.push({inf,i});
        qq.push({inf,1});
        int pos=0;
        // cerr<<1;
        while(!qq.empty()){
            // cerr<<2;
            int x=qq.top().fi,id=qq.top().sd;
            qq.pop();
            // cout<<"S:"<<x<<" "<<id<<"\n";
            while(!q.empty()){
                // cerr<<3;
                int X=q.top().fi,ID=q.top().sd;
                q.pop();
                if(a[ID]<=x-pos){
                    pos+=a[ID];
                    // cout<<"us1:"<<ID<<"\n";
                }
                else{
                    // cout<<"us2:"<<ID<<"\n";
                    a[ID]-=(x-pos),pos=x;
                    if(id!=ID) q.push({X,ID});
                    break;
                }
            }
            if(pos<x) break;
            a[id]=b[id];
            qq.push({inf,id});
            q.push({inf,id});
        }
        printf("%lld\n",pos);
        for(int i=1;i<=n;i++) vis[i]=0;
    }
    return 0;   
}