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#include <bits/stdc++.h>

using namespace std;
using ll = int64_t;

ll bfs(int n, const vector<ll> &routers, const vector<vector<pair<int, ll>>> &graph)
{
    queue<pair<int, ll>> q;
    q.emplace(0, 1);
    ll max_strength = -1;

    while (!q.empty())
    {
        auto [node, strength] = q.front();
        q.pop();

        if (strength > routers[node]) continue;

        if (node == n - 1)
        {
            max_strength = max(max_strength, strength);
        }

        for (auto [next, weight] : graph[node])
        {
            if (strength > LLONG_MAX / weight) continue;
            ll new_strength = strength * weight;

            if (new_strength <= routers[next])
            {
                q.emplace(next, new_strength);
            }
        }
    }

    return max_strength;
}

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

    int T;
    scanf("%d", &T);

    while (T--)
    {
        int n, m;
        scanf("%d %d", &n, &m);

        vector<ll> routers(n);
        for (int i = 0; i < n; i++)
        {
            scanf("%lld", &routers[i]);
        }

        vector<vector<pair<int, ll>>> graph(n);
        for (int i = 0; i < m; i++)
        {
            int a, b;
            ll w;
            scanf("%d %d %lld", &a, &b, &w);
            --a, --b;
            graph[a].emplace_back(b, w);
        }

        ll max_strength = bfs(n, routers, graph);
        printf("%lld\n", max_strength);
    }

    return 0;
}