#include <bits/stdc++.h>
using namespace std;
#define int long long
#define re register
#define lowbit(x) (x & (-x))
typedef pair<int, int> PII;
const int INF = 1e18;
const int N = 1e5 + 10;
void solve()
{
    int n, m;
    cin >> n >> m;
    vector<int> a(n + 1);
    int sum = 0;
    for (int i = 1; i <= n; i++)
        cin >> a[i], sum += a[i];
    int now = 0, ans = 0, la = 0, f = 0, ll = 0, ma = sum;
    while (m--)
    {
        int l, p;
        cin >> l >> p;
        la = l;
        l -= ll;
        if (f)
            continue;
        
        if (a[p] - now >= l)
        {
            if (now)
            {
                now -= a[p] - l;
                sum += a[p] - l;
            }
            ans += l;
        }
        else if (a[p] >= l)
        {
            ans += l;
        }
        else if (sum >= l)
        {
            sum -= (l - a[p]);
            now += l - a[p];
            ans += l;
        }
        else
            f = 1;
        ll = la;
    }
    ans += sum;
    cout << ans << '\n';
}
int T = 1;
signed main()
{
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    cin >> T;
    while (T--)
        solve();
    return 0;
}