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// Arti1990, II UWr

#include <bits/stdc++.h>

#define forr(i, n)                  for(int i=0; i<n; i++)
#define FOREACH(iter, coll)         for(auto iter = coll.begin(); iter != coll.end(); ++iter)
#define FOREACHR(iter, coll)        for(auto iter = coll.rbegin(); iter != coll.rend(); ++iter)
#define lbound(P,K,FUN)             ({auto SSS=P, PPP = P-1, KKK=(K)+1; while(PPP+1!=KKK) {SSS = (PPP+(KKK-PPP)/2); if(FUN(SSS)) KKK = SSS; else PPP = SSS;} PPP;})
#define testy()                     int _tests; cin>>_tests; FOR(_test, 1, _tests)
#define CLEAR(tab)                  memset(tab, 0, sizeof(tab))
#define CONTAIN(el, coll)           (coll.find(el) != coll.end())
#define FOR(i, a, b)                for(int i=a; i<=b; i++)
#define FORD(i, a, b)               for(int i=a; i>=b; i--)
#define MP                          make_pair
#define PB                          push_back
#define ff                          first
#define ss                          second
#define deb(X)                      X;
#define SIZE(coll) 					((int)coll.size())

#define M 1000000007
#define INF 1000000007LL

using namespace std;

int n, m, a, b;
long long w, limit;

struct wierzcholek
{
    long long p;
    vector <pair<long long, long long>> l, back; // <nr, waga>
    set <long long> przod; // <mult>
    map <long long, long long> tyl; // <mult, max_limit>
};
wierzcholek tab[1007];

void dfs(int nr, long long val)
{
    if(val > limit || val > tab[nr].p || tab[nr].przod.count(val) > 0)
        return;
//    cout << "wchodzi do " << nr << " z wartoscia " << val << '\n';
    tab[nr].przod.insert(val);
    for(auto p : tab[nr].l)
    {
        dfs(p.ff, val * p.ss);
    }
}

void dfs_b(int nr, long long mult, long long maks)
{
    if(mult > limit || (tab[nr].tyl[mult] >= maks))
        return;
//    cout << "wchodzi od tylu do " << nr << " z mult " << mult << " i maksem " << maks << '\n';
    tab[nr].tyl[mult] = maks;
    for(auto p : tab[nr].back)
    {
        dfs_b(p.ff, mult * p.ss, min(maks/p.ss, tab[p.ff].p));
    }
}

void dijkstra_b()
{
    priority_queue <pair<long long, pair<int, long long>>> pq; // <maks, <nr, mult>>
    pq.push({tab[n].p, {n, 1}});
    tab[n].tyl[1] = tab[n].p;
    while(!pq.empty())
    {
        auto x = pq.top();
        pq.pop();
        long long maks = x.ff;
        int nr = x.ss.ff;
        long long mult = x.ss.ss;

        if(tab[nr].tyl[mult] < maks)
            continue;

        for(auto p : tab[nr].back)
        {
            long long mult2 = mult*p.ss;
            int nr2 = p.ff;
            long long maks2 = min(maks/p.ss, tab[nr2].p);

            if(mult2 <= limit && tab[nr2].tyl[mult2] < maks2)
            {
                tab[nr2].tyl[mult2] = maks2;
                pq.push({maks2, {nr2, mult2}});
            }
        }
    }
}

int solve()
{
    cin >> n >> m;
    FOR(i, 1, n)
    {
        cin >> tab[i].p;
        tab[i].l.clear();
        tab[i].back.clear();
        tab[i].przod.clear();
        tab[i].tyl.clear();
    }
    forr(i, m)
    {
        cin >> a >> b >> w;
        tab[a].l.PB({b, w});
        tab[b].back.PB({a, w});
    }
    limit = sqrt(tab[n].p)+1;
    dfs(1, 1);
    //dfs_b(n, 1, tab[n].p);
    dijkstra_b();

    long long res = -1;

    if(n == 1)
        res = 1;

    FOR(a, 1, n)
        for(auto p : tab[a].l)
        {
            b = p.ff;
            w = p.ss;
            for(auto el2 : tab[b].tyl)
            {
                auto it = tab[a].przod.upper_bound(el2.ss / w);
                if(it == tab[a].przod.begin())
                    continue;
                it--;
                int el = *it;
                if(el*w <= el2.ss)
                {
                    res = max(res, el * w * el2.ff);
                }
            }
        }

    cout << res << '\n';

    return 0;
}

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

    testy()
        solve();

    return 0;
}