#include <bits/stdc++.h>
#define ll long long
using namespace std;
const int maxn = 1e5 + 7;
ll n, m;
ll a[maxn], x[maxn], t[maxn];

void solve() {
    cin >> n >> m;
    ll sum = 0;
    for (int i = 1; i <= n; i++) {
        cin >> a[i];
        sum += a[i];
    }
    ll pos = 0;
    for (int i = 1; i <= m; i++) {
        cin >> x[i] >> t[i];
    }
    m++;
    x[m] = 1e18;
    for (int i = 1; i <= m; i++) {
        if (pos + sum < x[i]) {
            cout << pos + sum << '\n';
            return;
        }
        if (pos + a[t[i]] < x[i]) {
            pos += a[t[i]];
        } else {
            pos = x[i];
        }
    }
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int T;
    cin >> T;
    while (T--) {
        solve();
    }
}