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

constexpr int MAX_N = 1e2, MAX_M = 2e2;
constexpr int SQRT = 31622;

int t, n, m;
int p[MAX_N + 1];
int a, b, w;

int prev_n;

set<pair<int, int>> adj[MAX_N + 1], adj_rev[MAX_N + 1];

bitset<SQRT + 1> visited_sqrt[MAX_N + 1];
set<int> visited_big[MAX_N + 1];

unordered_map<int, int> visited_rev[MAX_N + 1];

vector<int> strengths;
int ans;

void DFS(int v = 1, int strength = 1) {
    stack<pair<int, int>> St({{v, strength}});
    visited_sqrt[v][strength] = true;

    while(!St.empty()) {
        auto [v, strength] = St.top();
        St.pop();
        
        for(pair<int, int> u : adj[v]) {
            long long new_strength = (long long)strength * u.second;
    
            if(new_strength <= p[u.first]) {
                if(new_strength <= SQRT && !visited_sqrt[u.first][new_strength]) {
                    visited_sqrt[u.first][new_strength] = true;
                    St.push({u.first, new_strength});
                }
                else if(visited_big[u.first].find(new_strength) == visited_big[u.first].end()) {
                    visited_big[u.first].insert(new_strength);
                }
            }
        }
    }
}

void DFessa(int v = n, int multiplier = 1, int max_entry = p[n]) {
    stack<tuple<int, int, int>> St({{v, multiplier, max_entry}});
    visited_rev[v][multiplier] = max_entry;

    while(!St.empty()) {
        auto [v, multiplier, max_entry] = St.top();
        St.pop();

        for(pair<int, int> u : adj_rev[v]) {
            long long new_multiplier = (long long)multiplier * u.second;
            int new_max_entry = min(max_entry, p[v]) / u.second;
            
            if(new_multiplier <= 1e9 && max_entry >= 1 && visited_rev[u.first][new_multiplier] < new_max_entry) {
                visited_rev[u.first][new_multiplier] = max(visited_rev[u.first][new_multiplier], new_max_entry);

                if(new_multiplier <= SQRT) {
                    St.push({u.first, new_multiplier, new_max_entry});
                }
            }
        }
    }
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);

    cin >> t;

    while(t--) {
        cin >> n >> m;

        for(int i = 1; i <= n; i++) {
            cin >> p[i];

            if(i <= min(prev_n, n)) {
                adj[i].clear();
                adj_rev[i].clear();
    
                visited_sqrt[i].reset();
                visited_big[i].clear();
    
                visited_rev[i].clear();
            }

            prev_n = n;
        }

        for(int i = 1; i <= m; i++) {
            cin >> a >> b >> w;

            adj[a].insert({b, w});
            adj_rev[b].insert({a, w});
        }
        
        DFS();
        DFessa();

        ans = -1;

        for(int i = 1; i <= n; i++) {
            strengths.clear();

            for(int j = 1; j <= SQRT; j++) {
                if(visited_sqrt[i][j]) {
                    strengths.push_back(j);
                }
            }

            for(int j : visited_big[i]) {
                strengths.push_back(j);
            }

            if(strengths.empty()) {
                continue;
            }

            for(auto j : visited_rev[i]) {
                int idx = upper_bound(strengths.begin(), strengths.end(), j.second) - strengths.begin();

                if(idx > 0) {
                    ans = max(ans, strengths[idx - 1] * j.first);
                }
            }
        }
        
        cout << ans << '\n';
    }
}