#include<bits/stdc++.h>
#define ll long long
#define N 1000005
using namespace std;
int n,m;
ll full_a[N],a[N],x[N];
int last[N],fst[N],nxt[N],t[N];
void work(){
    scanf("%d%d",&n,&m);
    for (int i=1;i<=n;i++){
        scanf("%d",&full_a[i]);
        a[i]=full_a[i];
        last[i]=0;
        fst[i]=0;
    }
    for (int i=1;i<=m;i++){
        scanf("%d%d",&x[i],&t[i]);
        if (!fst[t[i]]) fst[t[i]]=i;
        nxt[last[t[i]]]=i;
        last[t[i]]=i;
    }
//    for (int i=1;i<=m;i++) printf("%d",nxt[i]); puts("");
//    for (int i=1;i<=n;i++) printf("%d",fst[i]); puts("");
    ll no_charge = 0;
    ll now_len=0,now_dp=1;
    set<int>st;
    for (int i=1;i<=n;i++) if (fst[i]==0) no_charge+=a[i]; else st.insert(fst[i]);
    for (int i=1;i<=m;i++){
        while(now_len<x[i]){
            if (!st.empty()){
                int j = t[*st.begin()];
                ll mv_len = min(x[i]-now_len,a[j]);
                now_len+=mv_len;
                a[j]-=mv_len;
                if (a[j]==0) st.erase(st.begin());
            } else{
                ll mv_len = min(x[i]-now_len,no_charge);
                now_len+=mv_len;
                no_charge-=mv_len;
                break;
            }
        }
//        printf("%lld %lld\n",now_len,no_charge);
        if (st.find(i)!=st.end()) st.erase(i);
        if (now_len==x[i]){
            if (nxt[i]){
                st.insert(nxt[i]);
                a[t[i]]=full_a[t[i]];
            } else{
                no_charge+=full_a[t[i]];
            }
        } else break;
    }
    printf("%lld\n",now_len+no_charge);
}
int main(){
    int T;
    scanf("%d",&T);
    while(T--) work();
}