#include <bits/stdc++.h>
using namespace std;
using namespace chrono;

using ll = long long;
using ull = unsigned long long;

string to_string(const string &s) {
  return '"' + s + '"';
}

string to_string(bool b) {
  return b ? "true" : "false";
}

template <typename A, typename B>
string to_string(const pair<A, B> &p) {
  return "(" + to_string(p.first) + ", " + to_string(p.second) + ")";
}

template <typename T>
string to_string(const T &v) {
  string s = "{";
  bool first = true;
  for (const auto &it : v) {
    if (!first)
      s += ", ";
    else
      first = false;
    s += to_string(it);
  }
  return s += "}";
}

void debug_out() {
  cerr << endl;
}

template <typename T, typename... Args>
void debug_out(const T &first, const Args&... rest) {
  cerr << to_string(first) << " ";
  debug_out(rest...);
}

#define debug(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

auto startTime = high_resolution_clock::now();
int get_time() {
  auto stopTime = chrono::high_resolution_clock::now();
  auto duration = duration_cast<milliseconds>(stopTime - startTime);
  return duration.count(); // in ms
}

const ll INF = 1e18;

void solve() {
  int n, m;
  cin >> n >> m;

  vector<ll> a(n + 1, 0);

  for (int i = 1; i <= n; ++i) {
    cin >> a[i];
  }

  vector<pair<ll, ll>> r(m + 1);

  for (int i = 1; i <= m; ++i) {
    cin >> r[i].first >> r[i].second;
  }

  set<int> b;
  for (int i = 1; i <= n; ++i) {
    b.insert(i);
    r.push_back({INF, i});
  }

  vector<ll> rem = a;

  ll last = 0;
  int j = 1;

  auto pick_battery = [&](ll dist) {
    if (b.size() == 0)
      return false;

    int wb = -1;
    while (j < r.size()) {
      if (b.find(r[j].second) == b.end()) {
        ++j;
        continue;
      }

      wb = r[j].second;
      if (rem[wb] == 0)  {
        b.erase(wb);
        wb = -1;
        continue;
      }
      break;
    }

    while (wb == -1) {
      if (b.empty())
        return false;

      wb = *b.begin();
      if (rem[wb] == 0) {
        b.erase(wb);
        continue;
      }

      break;
    }

    ll t = min(dist, rem[wb]);
    rem[wb] -= t;

    last += t;
    return true;
  };

  for (int i = 1; i <= m + 1; ++i) {
    j = max(j, i);
    while (last < r[i].first) {
      if (!pick_battery(r[i].first - last)) {
        break;
      }
    }

    if (last < r[i].first)
      break;

    if (last == r[i].first) {
      b.insert(r[i].second);
      rem[r[i].second] = a[r[i].second];
    }
  }

  cout << last << "\n";
}

int main() {
  cin.tie(NULL);
  ios_base::sync_with_stdio(false);

  int t = 1;
  cin >> t;
  while (t--)
    solve();

  return 0;
}