#include <bits/stdc++.h>
using namespace std;

#define PII pair<int, int>
#define int long long
#define endl '\n'

const int N = 1e5 + 10;

void run()
{
    map<int, int> mp;

    int n, m;
    cin >> n >> m;

    int a[n + 1] = {}, b[n + 1] = {}, st[n + 1] = {};
    int sum = 0;

    for (int i = 0; i < n; i++)
    {
        cin >> a[i];
        b[i] = a[i];
    }

    vector<PII> p;
    for (int i = 0; i < m; i++)
    {
        int x, t;
        cin >> x >> t;
        p.push_back({x, t});
        st[t] = 1;
        mp[t] += 1;
    }

    for (int i = 0; i < n; i++)
        if (st[i] == 0)
            sum += a[i];

    int ls = 0;
    int prev = 0;
    int ans = 0;

    for (int i = 0; i < m; i++)
    {
        int dis = p[i].first - prev;
        for (int j = ls; j < m; j++)
        {
            if (a[p[j].second] >= dis)
            {
                a[p[j].second] -= dis;
                dis = 0;
                ls = j;
                mp[p[j].second] -= 1;
                break;
            }
            else
            {
                dis -= a[p[j].second];
                a[p[j].second] = 0;
                ls = j;
                mp[p[j].second] -= 1;
            }
        }

        if (dis)
        {
            if (sum >= dis)
            {
                sum -= dis;
                dis = 0;
            }
            else
            {
                dis -= sum;
                sum = 0;
            }
        }

        ans = ans + (p[i].first - prev) - dis;
        prev = p[i].first;
        a[p[i].second] = b[p[i].second];

        // cout << sum << endl;

        if (mp[p[i].second] <= 0 && st[p[i].second] == 1)
        {
            sum += b[p[i].second];
            st[p[i].second] = 0;
        }
    }

    ans += sum;
    cout << ans << endl;
}

signed main()
{
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);

    int tt = 1;
    cin >> tt;

    while (tt--)
        run();
}