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#include <cstdio>
#include <cstdint>
#include <vector>
#include <queue>
#include <stack>
#include <set>

using namespace std;

const int64_t INF = 1000000008LL;

typedef struct {
	int64_t min_mul_to_exit;
	int capacity;
	bool ach1, achn;
	vector<pair<int, int> > adj_out;
	vector<pair<int, int> > adj_in;
	vector<pair<int, int> > adj_out2;
	vector<pair<int, int> > adj_in2;
	set<int64_t> powers;
} router_t;

typedef struct {
	int from, to;
	int64_t power;
} transmitter_t;

void test_case() {
	int n, m;
	scanf("%d %d", &n, &m);
	vector<router_t> V;
	V.reserve(n + 8);
	for (int i = 0; i < n; ++i) {
		router_t r;
		r.ach1 = false;
		r.achn = false;
		r.min_mul_to_exit = (i == n - 1) ? 1 : INF;
		scanf("%d", &r.capacity);
		V.push_back(r);
	}
	for (int i = 0; i < m; ++i) {
		int a, b, w;
		scanf("%d %d %d", &a, &b, &w);
		V[a - 1].adj_out.push_back(make_pair(b - 1, w));
		V[b - 1].adj_in.push_back(make_pair(a - 1, w));
	}


	queue<int> q;
	q.push(0);
	while (!q.empty()) {
		int item = q.front();
		q.pop();
		if (V[item].ach1) {
			continue;
		}
		V[item].ach1 = true;
		for (vector<pair<int, int> >::iterator it = V[item].adj_out.begin(); it != V[item].adj_out.end(); it++) {
			q.push(it->first);
		}
	}
	if (!V[n - 1].ach1) {
		printf("-1\n");
		return;
	}
	q.push(n - 1);
	while (!q.empty()) {
		int item = q.front();
		q.pop();
		if (V[item].achn) {
			continue;
		}
		V[item].achn = true;
		for (vector<pair<int, int> >::iterator it = V[item].adj_in.begin(); it != V[item].adj_in.end(); it++) {
			q.push(it->first);
		}
	}
	for (int i = 0; i < n; ++i) {
		for (vector<pair<int, int> >::iterator it = V[i].adj_out.begin(); it != V[i].adj_out.end(); it++) {
			if (V[it->first].ach1 && V[it->first].achn) {
				V[i].adj_out2.push_back(*it);
				V[it->first].adj_in2.push_back(make_pair(i, it->second));
			}
		}
	}


	vector<transmitter_t> E;
	for (int i = 0; i < n; ++i) {
		for (vector<pair<int, int> >::iterator it = V[i].adj_out2.begin(); it != V[i].adj_out2.end(); it++) {
			transmitter_t tr;
			tr.from = i;
			tr.to = it->first;
			tr.power = it->second;
			E.push_back(tr);
		}
	}
	bool modified = true;
	while (modified) {
		modified = false;
		for (vector<transmitter_t>::iterator it = E.begin(); it != E.end(); it++) {
			int64_t new_mul = V[it->to].min_mul_to_exit * it->power;
			if (new_mul >= INF) {
				new_mul = INF;
			}
			if (new_mul < V[it->from].min_mul_to_exit) {
				V[it->from].min_mul_to_exit = new_mul;
				modified = true;
			}
		}
	}


	stack<pair<int, int64_t> > st;
	st.push(make_pair(0, 1));
	while (!st.empty()) {
		pair<int, int64_t> item = st.top();
		st.pop();
		int node = item.first;
		int64_t power = item.second;
		if (V[node].capacity < power) {
			continue;
		}
		if (V[node].powers.contains(power)) {
			continue;
		}
		if (power * V[node].min_mul_to_exit >= INF) {
			continue;
		}
		V[node].powers.insert(power);
		for (vector<pair<int, int> >::iterator it = V[node].adj_out2.begin(); it != V[node].adj_out2.end(); it++) {
			st.push(make_pair(it->first, power * it->second));
		}
	}
	int64_t max = -1;
	for (set<int64_t>::iterator it = V[n - 1].powers.begin(); it != V[n - 1].powers.end(); it++) {
		if (*it > max) {
			max = *it;
		}
	}
	printf("%lld\n", max);
}

int main () {
	int T;
	scanf("%d", &T);
	for (int i = 0; i < T; ++i) {
		test_case();
	}
	return 0;
}