#include <iostream>
#include <cstdio>
#include <cctype>
#define il inline
#define ll long long
#define int long long
#define gc getchar
using namespace std;
il int read() {
    int x=0;bool f=0;char ch=gc();
    while(!isdigit(ch)) {f|=ch=='-';ch=gc();}
    while(isdigit(ch)) {x=(x<<1)+(x<<3)+(ch^48);ch=gc();}
    return f?-x:x;
}

const int N=1e5+10;
int T,n,m;
int a[N];
int x[N],t[N];

signed main() {
    T=read();
    while(T--) {
        n=read();m=read();
        int sum=0;
        for(int i=1;i<=n;++i) {
            a[i]=read();
            sum+=a[i];
        }
        for(int i=1;i<=m;++i) {
            x[i]=read();t[i]=read();
        }
        int xb=0;
        int cur = 0;
        for(int i=1;i<=m;++i) {
            if(x[i]-x[i-1]+cur>sum){
                break;
            }
            xb = i;
            cur+=x[i]-x[i-1];
            cur = max((int)0,cur-a[t[i]]);
        }
        printf("%lld\n",x[xb]+sum-cur);
    }
    return 0;
}