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#include <bits/stdc++.h>
using namespace std;
#define fwd(i, a, n) for (int i = (a); i < (n); i++)
#define rep(i, n)    fwd(i, 0, n)
#define all(X)       X.begin(), X.end()
#define sz(X)        int(X.size())
#define pb           push_back
#define eb           emplace_back
#define st           first
#define nd           second
using pii = pair<int, int>;
using vi = vector<int>;
using ll = long long;
using ld = long double;
#ifdef LOC
auto SS = signal(6, [](int) {
	*(int *)0 = 0;
});
#	define DTP(x, y)                                      \
		auto operator<<(auto &o, auto a)->decltype(y, o) { \
			o << "(";                                      \
			x;                                             \
			return o << ")";                               \
		}
DTP(o << a.st << ", " << a.nd, a.nd);
DTP(for (auto i : a) o << i << ", ", all(a));
void dump(auto... x) {
	((cerr << x << ", "), ...) << '\n';
}
#	define deb(x...) cerr << setw(4) << __LINE__ << ":[" #x "]: ", dump(x)
#else
#	define deb(...) 0
#endif

constexpr int SQ = 32000;
constexpr int max_n = 100;

int dist_to_n[max_n][SQ];

void run_dp(const vi &lim, const vector<vector<pii> > &g, int s) {
	vector<vi> unit_edges(sz(g));
	rep(i, sz(g)) {
		for (auto [v, w] : g[i]) {
			if (w == 1)
				unit_edges[i].pb(v);
		}
	}
	rep(i, sz(g)) fill(dist_to_n[i], dist_to_n[i] + SQ, 0);
	dist_to_n[s][1] = lim[s];
	vi component_dp(sz(g));
	vi component_vis(sz(g));
	priority_queue<pii> pq;
	fwd(d, 1, SQ) {
		fill(all(component_dp), 0);
		fill(all(component_vis), 0);
		rep(i, sz(g)) pq.push({min(dist_to_n[i][d], lim[i]), i});
		while (sz(pq)) {
			auto [dist, v] = pq.top();
			pq.pop();
			if (component_vis[v])
				continue;
			component_vis[v] = 1;
			component_dp[v] = dist;
			for (auto u : unit_edges[v]) {
				int new_dist = min(dist, lim[u]);
				pq.push({new_dist, u});
			}
		}
		rep(i, sz(g)) {
			dist_to_n[i][d] = component_dp[i];
			for (auto [v, w] : g[i]) {
				if (w > 1 && d * w < SQ)
					dist_to_n[v][d * w] =
						max(dist_to_n[v][d * w], dist_to_n[i][d] / w);
			}
		}
	}
}

bitset<SQ> vis_from_1[max_n];

void run_bfs(const vi &lim, const vector<vector<pii> > &g, int s) {
	vi min_lim(lim);
	for (auto &x : min_lim)
		x = min(x, SQ - 1);
	vector<vi> unit_edges(sz(g));
	rep(i, sz(g)) {
		for (auto [v, w] : g[i]) {
			if (w == 1)
				unit_edges[i].pb(v);
		}
	}
	vi component_vis(sz(g));
	vi dfs_stack;
	rep(i, sz(g)) vis_from_1[i].reset();
	vis_from_1[s][1] = 1;
	fwd(d, 1, SQ) {
		fill(all(component_vis), 0);
		rep(i, sz(g)) if (vis_from_1[i][d]) dfs_stack.pb(i);
		while (sz(dfs_stack)) {
			int v = dfs_stack.back();
			dfs_stack.pop_back();
			if (component_vis[v])
				continue;
			component_vis[v] = 1;
			for (auto u : unit_edges[v]) {
				if (min_lim[u] >= d)
					dfs_stack.pb(u);
			}
		}
		rep(i, sz(g)) {
			vis_from_1[i][d] = component_vis[i];
			if (vis_from_1[i][d]) {
				for (auto [v, w] : g[i]) {
					if (w > 1 && d * w <= min_lim[v])
						vis_from_1[v][d * w] = 1;
				}
			}
		}
	}
}

void sol() {
	int n, m;
	cin >> n >> m;
	vi lim(n);
	rep(i, n) cin >> lim[i];
	vector<vector<pii> > g(n), rg(n);
	vector<array<int, 3> > edges = {{0, 0, 1}};
	rep(i, m) {
		int v, u, w;
		cin >> v >> u >> w;
		v -= 1, u -= 1;
		if (w < SQ) {
			g[v].pb({u, w});
			rg[u].pb({v, w});
		}
		edges.pb({v, u, w});
	}
	run_bfs(lim, g, 0);
	run_dp(lim, rg, n - 1);
	int ans = 0;
	for (auto [s, t, w] : edges) {
		int best_ptr = 1;
		int best = 0;
		int best_dist = 0;
		for (int r = SQ - 1; r >= 1; r--) {
			best_dist = max(best_dist, dist_to_n[t][r]);
			while (best_ptr < SQ && 1ll * best_ptr * w <= best_dist) {
				if (vis_from_1[s][best_ptr])
					best = best_ptr;
				best_ptr += 1;
			}
			ans = max(ans, best * w * r);
		}
	}
	if (ans == 0)
		ans = -1;
	cout << ans << '\n';
}

int32_t main() {
	cin.tie(0)->sync_with_stdio(0);
	cout << fixed << setprecision(10);
	constexpr int max_val = 1e9 + 7;
	assert((SQ - 1) * (SQ - 1) > max_val);
	int t;
	cin >> t;
	rep(i, t) sol();
#ifdef LOCF
	cout.flush();
	cerr << "- - - - - - - - -\n";
	(void)!system(
		"grep VmPeak /proc/$PPID/status | sed s/....kB/\' MB\'/1 >&2"); // 4x.kB
																		// ....kB
#endif
}