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#include<iostream>
#include<vector>
#include<set>
#include<unordered_set>
#include<algorithm>
#include<bitset>
using namespace std;

long long M = 1;

struct route {
    long long router;
    long long power;
};

bool operator<(const route &a, const route &b) {
    if (a.power < b.power) return true;
    if (a.power > b.power) return false;
    if (a.router < b.router) return true;
    return false;
}

inline long long get_key(long long router, long long power) {
    return (power << M) + router;
}

const long long H = 4'000'000'000;
bitset<H> visited_small;

int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);

    int t;
    cin >> t;

    while (t--) {
        int n, m;
        cin >> n >> m;

        M = 1;
        while (1 << M <= n) {
            M++;
        }

        vector<long long> max_powers(n);
        for (int i = 0; i < n; i++) {
            cin >> max_powers[i];
        }
        for (int i = 0; i < n; i++) {
            max_powers[i] = min(max_powers[i], max_powers[n - 1]);
        }
        
        vector<set<route>> routes_set(n);
        for (int i = 0; i < m; i++) {
            long long u, v, w;
            cin >> u >> v >> w;
            u--;
            v--;
            if (u == v && w == 1) continue;
            if (w > max_powers[v]) continue;
            routes_set[u].insert({v, w});            
        }
        
        vector<vector<route>> routes(n);
        for (int i = 0; i < n; i++) {
            for (route r: routes_set[i]) {
                routes[i].push_back(r);
            }            
        }        

        long long result = -1;
        if (n == 1) {
            result = 1;
        }
        // long long small_hits = 0;
        // long long large_hits = 0;
        
        vector<route> lst;
        lst.reserve(20'000'000);
        lst.push_back({0, 1});

        visited_small.reset();
        visited_small.set(get_key(0, 1));

        unordered_set<long long> visited_large;
        visited_large.reserve(20'000);

        for (int i = 0; i < lst.size(); i++) {
            route u = lst[i];

            for (route v : routes[u.router]) {
                long long power = u.power * v.power;
                if (power > max_powers[v.router]) continue;

                long long key = get_key(v.router, power);
                if (key < H) {
                    // small_hits++;
                    if (visited_small.test(key)) continue;
                    visited_small.set(key);
                }
                else {
                    // large_hits++;
                    if (visited_large.count(key)) continue;
                    visited_large.insert(key);
                }
                
                lst.push_back({v.router, power});
                if (v.router == n - 1) {
                    result = max(result, power);
                }
            }
        }
        // cerr << "small hits: " << small_hits << endl;
        // cerr << "large hits: " << large_hits << endl;
        // cerr << "elements processed: " << lst.size() << endl;
        cout << result << endl;
    }

    return 0;
}