#include <bits/stdc++.h>
using namespace std;
#define int long long
#define sz(a) (int)(a.size())

signed main()
{
    int T;
    cin>>T;
    while(T--){
        int n, m;
        cin >> n >> m;
        int sum = 0;
        vector<int>a(n),x(m),t(m),d(m+1,4e18);
        for(int i=0;i<n;i++){
            cin>>a[i];
            sum += a[i];
        }
        for(int i=0;i<m;i++){
            cin>>x[i]>>t[i];
            t[i]--;
        }
        for(int i=0;i<m;i++){
            if(!i)d[i] = x[i];
            else d[i] = x[i] - x[i-1];
        }
        int ans = 0;
        for(int i=0;i<m;i++){
            if(d[i] > sum)break;
            ans += min(d[i],a[t[i]]);
            int lf = max(0LL,d[i]-a[t[i]]);
            d[i+1] += lf;
        }
        ans += sum;
        cout<<ans<<'\n';
    }
    return 0;

}