#include "bits/stdc++.h"
#include <random>
#include <chrono>
#define ALL(x) (x).begin(), (x).end()
#define SZ(x) ((lint)(x).size())
#define FOR(i, begin, end) for(lint i=(begin),i##_end_=(end);i<i##_end_;++i)
#define IFOR(i, begin, end) for(lint i=(end)-1,i##_begin_=(begin);i>=i##_begin_;--i)
#define REP(i, n) FOR(i,0,n)
#define IREP(i, n) IFOR(i,0,n)
#define endk '\n'
using namespace std; typedef unsigned long long _ulong; typedef long long int lint; typedef long double ld; typedef pair<lint, lint> plint; typedef pair<ld, ld> pld;
struct fast_ios { fast_ios() { cin.tie(nullptr), ios::sync_with_stdio(false), cout << fixed << setprecision(20); }; } fast_ios_;
template<class T> auto add = [](T a, T b) -> T { return a + b; };
template<class T> auto f_max = [](T a, T b) -> T { return max(a, b); };
template<class T> auto f_min = [](T a, T b) -> T { return min(a, b); };
template<class T> using V = vector<T>;
using Vl = V<lint>; using VVl = V<Vl>;
template< typename T > ostream& operator<<(ostream& os, const vector< T >& v) {
	for (int i = 0; i < (int)v.size(); i++) os << v[i] << (i + 1 != v.size() ? " " : "");
	return os;
}
template< typename T >istream& operator>>(istream& is, vector< T >& v) {
	for (T& in : v) is >> in;
	return is;
}
template<class T> bool chmax(T& a, const T& b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> bool chmin(T& a, const T& b) { if (b < a) { a = b; return 1; } return 0; }
lint gcd(lint a, lint b) { if (b == 0) return a; else return gcd(b, a % b); }
lint ceil(lint a, lint b) { return (a + b - 1) / b; }
lint digit(lint a) { return (lint)log10(a); }
lint e_dist(plint a, plint b) { return abs(a.first - b.first) * abs(a.first - b.first) + abs(a.second - b.second) * abs(a.second - b.second); }
lint m_dist(plint a, plint b) { return abs(a.first - b.first) + abs(a.second - b.second); }
bool check_overflow(lint a, lint b, lint limit) { if (b == 0) return false; return a > limit / b; } // a * b > c => true
void Worshall_Floyd(VVl& g) { REP(k, SZ(g)) REP(i, SZ(g)) REP(j, SZ(g)) chmin(g[i][j], g[i][k] + g[k][j]); }
const lint MOD1000000007 = 1000000007, MOD998244353 = 998244353, INF = 5e18;
lint dx[8] = { 1, 0, -1, 0, 1, -1, 1, -1 }, dy[8] = { 0, 1, 0, -1, -1, -1, 1, 1 };
bool YN(bool flag) { cout << (flag ? "YES" : "NO") << endk; return flag; } bool yn(bool flag) { cout << (flag ? "Yes" : "No") << endk; return flag; }
struct Edge {
	lint from, to;
	lint cost;
	Edge() {

	}
	Edge(lint u, lint v, lint c) {
		cost = c;
		from = u;
		to = v;
	}
	bool operator<(const Edge& e) const {
		return cost < e.cost;
	}
};
struct WeightedEdge {
	lint to;
	lint cost;
	WeightedEdge(lint v, lint c = 1) {
		to = v;
		cost = c;
	}
	bool operator<(const WeightedEdge& e) const {
		return cost < e.cost;
	}
};
using WeightedGraph = V<V<WeightedEdge>>;
typedef pair<lint, plint> tlint;
typedef pair<plint, plint> qlint;
typedef pair<char, lint> valchar;


Vl arr;
lint N, M, u, v, c;
lint Dijkstra(WeightedGraph& g, int s) {
	VVl dist(SZ(g), Vl(1002, INF));
	VVl visited(SZ(g), Vl(1002, 0));
	priority_queue<tlint, vector<tlint>, greater<tlint>> que;
	que.push({ 0, {s, 0} });
	dist[s][0] = 0;
	while (!que.empty()) {
		tlint curr = que.top(); que.pop();
		if (visited[curr.second.first][curr.second.second]) continue;
		visited[curr.second.first][curr.second.second] = true;
		if (dist[curr.second.first][curr.second.second] < curr.first) continue;
		for (auto nxt : g[curr.second.first]) {
			lint nxt_p = min(1001ll, curr.second.second + arr[curr.second.first]);
			if (visited[nxt.to][nxt_p]) continue;
			if (chmin(dist[nxt.to][nxt_p], curr.first + nxt.cost / nxt_p + arr[curr.second.first])) {
				que.push({ dist[nxt.to][nxt_p], {nxt.to, nxt_p} });
			}
		}
	}
	return *min_element(ALL(dist[N - 1]));
}

int main() {
	cin >> N >> M;
	WeightedGraph to(N);
	arr.assign(N, 0);
	REP(i, M) {
		cin >> u >> v >> c; u--; v--;
		to[u].push_back({ v, c });
		to[v].push_back({ u, c });
	}
	cin >> arr;
	cout << Dijkstra(to, 0) << endk;

}