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// PA 2024 5B - Heavy metal
#include <iostream>
#include <string>
#include <vector>
#include <queue>
#include <unordered_set>
#include <algorithm>
using namespace std;

struct pair_hash {
    inline std::size_t operator()(const std::pair<int,int> & v) const {
        return v.first*31+v.second;
    }
};

vector<vector<long long>> edgeMult;
vector<vector<long long>> edgeDest;
vector<long long> vCap;
long long t, n, m, p, a, b, w, res, newVal;
unordered_set<pair<long long, long long>, pair_hash> visited;

void dfs(long long curr, long long val) {
	if (val > vCap[curr]) {
		return;
	}
	if (visited.find(make_pair(curr, val)) != visited.end()) {
		return;
	}
	visited.insert(make_pair(curr, val));	
	
	if (curr == n - 1 && res < val) {
		res = val;
	}
	for (unsigned long long i = 0; i < edgeDest[curr].size(); ++i) {
		newVal = val * edgeMult[curr][i];
		dfs(edgeDest[curr][i], newVal);
	}
}

int main()
{
	ios_base::sync_with_stdio(0);
	
	cin >> t;
	
	for (long long i = 0; i < t; ++i) {
		edgeMult.clear();
		edgeDest.clear();
		vCap.clear();
		visited.clear();
		cin >> n;
		cin >> m;
		
		for (long long j = 0; j < n; ++j) {
			cin >> p;
			vCap.push_back(p);
			edgeMult.push_back(vector<long long>());
			edgeDest.push_back(vector<long long>());
		}
		
		for (long long j = 0; j < m; ++j) {
			cin >> a;
			cin >> b;
			cin >> w;
			--a;
			--b;
			edgeMult[a].push_back(w);
			edgeDest[a].push_back(b);
		}
		
		res = -1;
		dfs(0, 1);
		cout << res << endl;
	}	
	
	return 0;
}