#include "bits/stdc++.h"
#define int long long
using namespace std;
using ll = long long;
using P = pair<ll, pair<ll, ll>>;
const ll INF = (1LL << 61);
ll mod = 1000000007;
int N, M;
vector<pair<ll, ll>>edge[110];
int T[110];

vector<vector<ll>> dijkstra(int s) {
	priority_queue<P, vector<P>, greater<P>>pq;
	// しおむすびを合計t分食べているという情報を追加
	vector<vector<ll>>dist(N, vector<ll>(1010, INF));
	dist[s][T[s]] = T[s];
	pq.push({ dist[s][T[s]],{s, T[s] } });
	while (!pq.empty()) {
		P p = pq.top(); pq.pop();
		ll d = p.first, from = p.second.first, t = p.second.second;
		if (dist[from][t] < d)continue;
		for (auto nv : edge[from]) {
			ll to = nv.first; ll cost = nv.second;
			cost /= t;
			if (to != N)cost += T[to];
			if (dist[from][t] + cost < dist[to][min(1001LL, t + T[to])]) {
				dist[to][min(1001LL, t + T[to])] = dist[from][t] + cost;
				pq.push({ dist[to][min(1001LL, t + T[to])],{to, min(1001LL, t + T[to])} });
			}
		}
	}
	return dist;
}
signed main() {
	ios::sync_with_stdio(false);
	cin.tie(0);
	cin >> N >> M;
	for (int i = 0; i < M; i++) {
		int A, B, C; cin >> A >> B >> C; A--; B--;
		edge[A].push_back({ B,C });
		edge[B].push_back({ A,C });
	}
	for (int i = 0; i < N; i++)cin >> T[i];
	auto ans = dijkstra(0);
	int res = INF;
	for (int i = 0; i < 1010; i++)res = min(res, ans[N - 1][i]);
	cout << res << endl;
	return 0;
}