#line 2 "/Users/tiramister/CompetitiveProgramming/Cpp/CppLibrary/Graph/graph.hpp"

#include <vector>

template <class Cost = int>
struct Edge {
    int src, dst;
    Cost cost;

    Edge() = default;
    Edge(int src, int dst, Cost cost = 1)
        : src(src), dst(dst), cost(cost){};

    bool operator<(const Edge<Cost>& e) const { return cost < e.cost; }
    bool operator>(const Edge<Cost>& e) const { return cost > e.cost; }
};

template <class Cost = int>
struct Graph : public std::vector<std::vector<Edge<Cost>>> {
    using std::vector<std::vector<Edge<Cost>>>::vector;

    void span(bool direct, int src, int dst, Cost cost = 1) {
        (*this)[src].emplace_back(src, dst, cost);
        if (!direct) (*this)[dst].emplace_back(dst, src, cost);
    }
};
#line 2 "/Users/tiramister/CompetitiveProgramming/Cpp/CppLibrary/Tools/heap_alias.hpp"

#include <queue>

template <class T>
using MaxHeap = std::priority_queue<T>;
template <class T>
using MinHeap = std::priority_queue<T, std::vector<T>, std::greater<T>>;
#line 3 "main.cpp"
#include <iostream>
#include <algorithm>
#line 6 "main.cpp"

using namespace std;
constexpr int INF = 1 << 30;
constexpr int C = 1000;

void solve() {
    int n, m;
    cin >> n >> m;

    Graph<int> graph(n);
    while (m--) {
        int u, v, c;
        cin >> u >> v >> c;
        graph.span(false, --u, --v, c);
    }

    vector<int> ts(n);
    for (auto& t : ts) cin >> t;

    auto dp = vector(n, vector(C + 2, INF));
    // 食べた時間がCより大なら、移動時間は常に0なので区別不要
    MinHeap<tuple<int, int, int>> heap;
    // 時間, 頂点, おにぎり時間

    dp[0][ts[0]] = ts[0];
    heap.emplace(ts[0], 0, ts[0]);

    while (!heap.empty()) {
        auto [d, v, t] = heap.top();
        heap.pop();
        if (dp[v][t] < d) continue;

        for (auto e : graph[v]) {
            auto u = e.dst;
            auto nd = d + e.cost / t + ts[u];
            auto nt = min(C + 1, t + ts[u]);

            if (nd >= dp[u][nt]) continue;
            dp[u][nt] = nd;
            heap.emplace(nd, u, nt);
        }
    }

    cout << *min_element(dp[n - 1].begin(), dp[n - 1].end()) << "\n";
}

int main() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);

    solve();

    return 0;
}