#define _USE_MATH_DEFINES
#include <bits/stdc++.h>
using namespace std;
#define FOR(i,m,n) for(int i=(m);i<(n);++i)
#define REP(i,n) FOR(i,0,n)
#define ALL(v) (v).begin(),(v).end()
using ll = long long;
constexpr int INF = 0x3f3f3f3f;
constexpr long long LINF = 0x3f3f3f3f3f3f3f3fLL;
constexpr double EPS = 1e-8;
constexpr int MOD = 1000000007;
// constexpr int MOD = 998244353;
constexpr int dy[] = {1, 0, -1, 0}, dx[] = {0, -1, 0, 1};
constexpr int dy8[] = {1, 1, 0, -1, -1, -1, 0, 1}, dx8[] = {0, -1, -1, -1, 0, 1, 1, 1};
template <typename T, typename U> inline bool chmax(T &a, U b) { return a < b ? (a = b, true) : false; }
template <typename T, typename U> inline bool chmin(T &a, U b) { return a > b ? (a = b, true) : false; }
struct IOSetup {
  IOSetup() {
    std::cin.tie(nullptr);
    std::ios_base::sync_with_stdio(false);
    std::cout << fixed << setprecision(20);
  }
} iosetup;

template <typename CostType>
struct Edge {
  int src, dst; CostType cost;
  Edge(int src, int dst, CostType cost = 0) : src(src), dst(dst), cost(cost) {}
  inline bool operator<(const Edge &x) const {
    return cost != x.cost ? cost < x.cost : dst != x.dst ? dst < x.dst : src < x.src;
  }
  inline bool operator<=(const Edge &x) const { return !(x < *this); }
  inline bool operator>(const Edge &x) const { return x < *this; }
  inline bool operator>=(const Edge &x) const { return !(*this < x); }
};

int main() {
  constexpr int M = 1001;
  int n, m; cin >> n >> m;
  vector<vector<Edge<int>>> graph(n);
  while (m--) {
    int a, b, c; cin >> a >> b >> c; --a; --b;
    graph[a].emplace_back(a, b, c);
    graph[b].emplace_back(b, a, c);
  }
  vector<int> t(n); REP(i, n) cin >> t[i];
  vector dist(n, vector(M + 1, INF));
  dist[0][t[0]] = t[0];
  priority_queue<pair<int, pair<int, int>>, vector<pair<int, pair<int, int>>>, greater<pair<int, pair<int, int>>>> que;
  que.emplace(t[0], make_pair(0, t[0]));
  while (!que.empty()) {
    auto [cost, ij] = que.top(); que.pop();
    auto [i, j] = ij;
    if (cost > dist[i][j]) continue;
    for (const Edge<int> &e : graph[i]) {
      int nx_cost = dist[i][j] + e.cost / j + t[e.dst], nx_j = min(j + t[e.dst], M);
      if (nx_cost < dist[e.dst][nx_j]) {
        dist[e.dst][nx_j] = nx_cost;
        que.emplace(nx_cost, make_pair(e.dst, nx_j));
      }
    }
  }
  cout << *min_element(ALL(dist[n - 1])) << '\n';
  return 0;
}