#include <bits/stdc++.h>
using namespace std;
#define rep(i, x, y) for (int i = (x); i <= (y); ++i)
#define per(i, x, y) for (int i = (x); i >= (y); --i)
const int P = 998244353;
const int N = 1e6 + 10;
typedef long long ll;
#define int long long
void solve() {
    int n, m;
    cin >> n >> m;
    vector<ll> a(n + 1);
    vector<ll> val(n + 1);
    rep(i, 1, n) {
        cin >> a[i];
        val[i] = a[i];
    }
    deque<ll> q;
    vector<ll> x(m + 1), t(m + 1);
    ll tot_trash = 0;
    vector<bool> vis(n + 1);
    vector<int> cnt(n + 1);
    rep(i, 1, m) {
        cin >> x[i] >> t[i];
        q.push_back(t[i]);
        cnt[t[i]]++;
        vis[t[i]] = true;
    }
    rep(i, 1, n) if (!vis[i]) tot_trash += a[i];
    vector<int> owe(n + 1);
    rep(i, 1, m) {
        ll need = x[i] - x[i - 1];
        while (!q.empty()) {
            int u = q.front();
            q.pop_front();
            if (a[u] == 0) {
                owe[u]++;
                continue;
            } else {
                if (a[u] <= need) {
                    need -= a[u], a[u] = 0;
                } else {
                    a[u] -= need;
                    need = 0;
                    if (u != t[i])
                        q.push_front(u);
                    break;
                }
            }
        }
        if (need) {
            if (need >= tot_trash) {
                need -= tot_trash;
                ll ans = x[i] - need;
                cout << ans << '\n';
                return;
            } else {
                tot_trash -= need;
            }
        }
        if (owe[t[i]] > 0) {
            q.push_front(t[i]);
            owe[t[i]]--;
        }
        a[t[i]] = val[t[i]];
        cnt[t[i]]--;
        if (cnt[t[i]] == 0) {
            
            tot_trash += a[t[i]];
            a[t[i]] = 0;
        }
    }
    ll ans = x[m] + tot_trash;
    rep(i, 1, n) {
        if (vis[i])
            ans += a[i];
    }
    cout << ans << '\n';
    return;
}
signed main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    int t = 1;
    cin >> t;
    while (t--)
        solve();
    return 0;
}