#include "bits/stdc++.h"

typedef long long ll;

using namespace std;
const int N = 2e5 + 10;
int n, m;
ll A[N], val[N];
ll x[N];
int t[N];

void solve() {
    cin >> n >> m;
    for (int i = 1; i <= n; i++) cin >> A[i], val[i] = A[i];
    for (int i = 1; i <= m; i++) cin >> x[i] >> t[i];
    t[m + 1] = 0;
    ll tmp = 0;
    int id = t[1], r = 1;
    for (int l = 1; l <= m; l++) {
        if (r == m + 1) break;
        if (tmp + val[id] >= x[l]) {
            val[id] -= x[l] - tmp;
            tmp = x[l];
            val[t[l]] = A[t[l]];
            id = t[++r];
        } else {
            while (r <= m && tmp + val[id] < x[l]) {
                tmp = val[id] + tmp;
                id = t[++r];
            }
            if (r == m + 1) {
                for (int i = 1; i <= n; i++) tmp += val[i];
                cout << tmp << '\n';
                return;
            }
            val[id] -= x[l] - tmp;
            tmp = x[l];
            val[t[l]] = A[t[l]];
            id = t[++r];
        }
    }
    for (int i = 1; i <= n; i++) {
        tmp += val[i];
    }
    cout << tmp << '\n';
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int _ = 1;
    cin >> _;
    while (_--) {
        solve();
    }
    return 0;
}
/*

1
3 1
3 3 3
8 1

 */