import java.io.*;
import java.util.*;

public class Main {
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner();
        int n = sc.nextInt();
        int m = sc.nextInt();
        ArrayList<HashMap<Integer, Integer>> graph = new ArrayList<>();
        for (int i = 0; i < n; i++) {
            graph.add(new HashMap<>());
        }
        for (int i = 0; i < m; i++) {
            int a = sc.nextInt() - 1;
            int b = sc.nextInt() - 1;
            int c = sc.nextInt();
            graph.get(a).put(b, c);
            graph.get(b).put(a, c);
        }
        int[] times = new int[n];
        for (int i = 0; i < n; i++) {
            times[i] = sc.nextInt();
        }
        PriorityQueue<Path> queue = new PriorityQueue<>();
        int[][] costs = new int[1002][n];
        for (int[] arr : costs) {
            Arrays.fill(arr, Integer.MAX_VALUE);
        }
        queue.add(new Path(0, 0, 0));
        while (queue.size() > 0) {
            Path p = queue.poll();
            if (costs[p.time][p.idx] <= p.value) {
                continue;
            }
            costs[p.time][p.idx] = p.value;
            p.time = Math.min(1001, p.time + times[p.idx]);
            p.value += times[p.idx];
            for (int x : graph.get(p.idx).keySet()) {
                queue.add(new Path(x, p.value + graph.get(p.idx).get(x) / p.time, p.time));
            }
        }
        int min = Integer.MAX_VALUE;
        for (int i = 0; i < 1002; i++) {
            min = Math.min(min, costs[i][n - 1]);
        }
        System.out.println(min);
    }
    
    static class Path implements Comparable<Path> {
        int idx;
        int value;
        int time;
        
        public Path(int idx, int value, int time) {
            this.idx = idx;
            this.value = value;
            this.time = time;
        }
        
        public int compareTo(Path another) {
            return value - another.value;
        }
    }
}
class Scanner {
    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    StringTokenizer st = new StringTokenizer("");
    
    public Scanner() throws Exception {
        
    }
    
    public int nextInt() throws Exception {
        return Integer.parseInt(next());
    }
    
    public long nextLong() throws Exception {
        return Long.parseLong(next());
    }
    
    public String next() throws Exception {
        if (!st.hasMoreTokens()) {
            st = new StringTokenizer(br.readLine());
        }
        return st.nextToken();
    }
}