#include <iostream>
#define ll long long
using namespace std;
ll ti, n, m;
ll w[100005];
ll x[100005];
ll t[100005];
ll p[100005];
ll q[100005];
int main()
{
    cin >> ti;
    while (ti--)
    {
        cin >> n >> m;
        ll sum = 0, s = 0,ans=0;
        for (ll i = 1; i <= n; ++i)
        {
            cin >> w[i];
            sum += w[i];
        }
        for (ll i = 1; i <= m; ++i)
        {
            cin >> x[i] >> t[i];
            p[i] = q[t[i]];
            q[t[i]] = i;
        }
        for (ll i = 1; i <= m; ++i)
        {
            ll ts = x[i] - x[i - 1];
            if (s + ts > sum)
                break;
            s += ts;
            ans += ts;
            ll tp = min(w[t[i]], x[i] - x[p[i]]);
            s -= tp;
        }
        ans += sum - s;
        cout << ans << endl;
        for (int i = 1; i <= n; ++i)
        {
            q[i] = 0;
            //x[i] = 0;
            //t[i] = 0;
            //w[i] = 0;
            //p[i] = 0;
        }
    }
    return 0;
}