#include<bits/stdc++.h>
using namespace std;
using i64 = long long;

signed main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    int T; cin >> T;
    while(T--){
        int n, m; cin >> n >> m;
        vector<i64> a(n);
        for(auto&x : a) cin >> x;
        vector<pair<int, int>> b(m);
        for(auto&[x, t] : b){
            cin >> x >> t; t--;
        }
        // sort(b.begin(), b.end());

        i64 usage = 0, ans = 0, sum = accumulate(a.begin(), a.end(), 0ll);
        int last = 0;
        for(auto[x, t] : b){
            auto d = x - last;
            usage += d;
            if(usage > sum){
                ans += (sum - (usage - d));
                break;
            }
            ans += d;
            usage -= min(usage, a[t]);
            last = x;
        }
        ans += max(0ll, sum - usage);
        cout << ans << '\n';
    }

    return 0;
}