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#include <bits/stdc++.h>
using namespace std;

void test_case() {
	int n, m;
	cin >> n >> m;
	vector<int> limit(n);
	for (int i = 0; i < n; i++) {
		cin >> limit[i];
	}
	vector<vector<pair<int,int>>> edges(n);
	auto inv = edges;
	for (int i = 0; i < m; i++) {
		int a, b, mul;
		cin >> a >> b >> mul;
		a--;
		b--;
		edges[a].emplace_back(b, mul);
		inv[b].emplace_back(a, mul);
	}
	
	int MAX = *max_element(limit.begin(), limit.end());
	int L1 = 3 * sqrt(MAX + 0.5); // 10^5
	int L2 = MAX / L1 + 2; // 10^4
	
	vector<vector<bool>> yes(L1 + 1, vector<bool>(n));
	yes[1][0] = true;
	for (int d = 1; d <= L1; d++) {
		vector<int> waiting;
		for (int a = 0; a < n; a++) {
			if (yes[d][a]) {
				for (auto [b, mul] : edges[a]) {
					if ((long long) d * mul <= min(L1,limit[b]) && !yes[d*mul][b]) {
						yes[d*mul][b] = true;
						if (mul == 1 && b < a) {
							waiting.push_back(b);
						}
					}
				}
			}
		}
		for (int i = 0; i < (int) waiting.size(); i++) {
			int a = waiting[i];
			assert(yes[d][a]);
			for (auto [b, mul] : edges[a]) {
				if ((long long) d * mul <= min(L1,limit[b]) && !yes[d*mul][b]) {
					yes[d*mul][b] = true;
					if (mul == 1) {
						waiting.push_back(b);
					}
				}
			}
		}
	}
	int answer = -1;
	for (int d = 1; d <= L1; d++) {
		if (yes[d][n-1]) {
			answer = d;
		}
	}
	
	vector<vector<int>> upTo(L1 + 1, vector<int>(n));
	for (int d = 1; d <= L1; d++) {
		upTo[d] = upTo[d-1];
		for (int a = 0; a < n; a++) {
			if (yes[d][a]) {
				upTo[d][a] = d;
			}
		}
	}
	
	vector<vector<int>> dp(L2 + 1, vector<int>(n));
	dp[1][n-1] = limit[n-1];
	for (int d = 1; d <= L2; d++) {
		set<pair<int,int>, greater<pair<int,int>>> s;
		for (int a = 0; a < n; a++) {
			if (dp[d][a]) {
				s.insert({dp[d][a], a});
			}
		}
		while (!s.empty()) {
			auto [me,a] = *s.begin();
			assert((long long) me * d <= limit[n-1]);
			s.erase(s.begin());
			if (dp[d][a] != me) {
				continue;
			}
			for (auto [b,mul] : inv[a]) {
				int big = upTo[min(L1,me/mul)][b];
				if (big) {
					answer = max(answer, big * mul * d);
				}
					
				if ((long long) d * mul <= L2) {
					int maybe = min(me / mul, limit[b]);
					if (maybe > dp[d*mul][b]) {
						dp[d*mul][b] = maybe;
						if (mul == 1) {
							s.insert({maybe, b});
						}
					}
				}
			}
		}
	}
	cout << answer << "\n";
}

int main() {
	int T;
	cin >> T;
	while (T--) {
		test_case();
	}
}