import java.util.*; import java.io.*; import java.math.*; public class Main{ //Don't have to see. start------------------------------------------ static class InputIterator{ ArrayList inputLine = new ArrayList<>(1024); int index = 0; int max; String read; InputIterator(){ BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); try{ while((read = br.readLine()) != null){ inputLine.addAll(Arrays.asList(read.split(" "))); } }catch(IOException e){} max = inputLine.size(); } boolean hasNext(){return (index < max);} String next(){ if(hasNext()){ return inputLine.get(index++); }else{ throw new IndexOutOfBoundsException("There is no more input"); } } } static HashMap CONVSTR = new HashMap<>(); static InputIterator ii = new InputIterator();//This class cannot be used in reactive problem. static PrintWriter out = new PrintWriter(System.out); static void flush(){out.flush();} static void myout(Object t){out.println(t);} static void myerr(Object t){System.err.print("debug:");System.err.println(t);} static String next(){return ii.next();} static boolean hasNext(){return ii.hasNext();} static int nextInt(){return Integer.parseInt(next());} static long nextLong(){return Long.parseLong(next());} static double nextDouble(){return Double.parseDouble(next());} static ArrayList nextCharArray(){return myconv(next(), 0);} static ArrayList nextStrArray(int size){ ArrayList ret = new ArrayList<>(size); for(int i = 0; i < size; i++){ ret.add(next()); } return ret; } static ArrayList nextIntArray(int size){ ArrayList ret = new ArrayList<>(size); for(int i = 0; i < size; i++){ ret.add(Integer.parseInt(next())); } return ret; } static ArrayList nextLongArray(int size){ ArrayList ret = new ArrayList<>(size); for(int i = 0; i < size; i++){ ret.add(Long.parseLong(next())); } return ret; } @SuppressWarnings("unchecked") static String myconv(Object list, int no){//only join String joinString = CONVSTR.get(no); if(list instanceof String[]){ return String.join(joinString, (String[])list); }else if(list instanceof ArrayList){ return String.join(joinString, (ArrayList)list); }else{ throw new ClassCastException("Don't join"); } } static ArrayList myconv(String str, int no){//only split String splitString = CONVSTR.get(no); return new ArrayList(Arrays.asList(str.split(splitString))); } public static void main(String[] args){ CONVSTR.put(8, " "); CONVSTR.put(9, "\n"); CONVSTR.put(0, ""); solve();flush(); } //Don't have to see. end------------------------------------------ static void solve(){//Here is the main function int N = nextInt(); int M = nextInt(); Node[] list = new Node[N]; for(int i = 0; i < N; i++){ list[i] = new Node(); } for(int i = 0; i < M; i++){ int A = nextInt() - 1; int B = nextInt() - 1; int C = nextInt(); list[A].child.add(new Edge(B, C)); list[B].child.add(new Edge(A, C)); } for(int i = 0; i < N; i++){ list[i].T = nextInt(); } PriorityQueue pq = new PriorityQueue<>(); pq.add(new Q(0, 0l, 0)); while(pq.size() > 0){ Q tmp = pq.poll(); int now = tmp.nx; long cost = tmp.cost; int sumT = tmp.sumT; list[now].cost = Math.min(list[now].cost, cost); ArrayList child = list[now].child; for(int i = 0; i < child.size(); i++){ Edge e = child.get(i); long nxCost = cost + list[now].T + (e.C / (sumT + list[now].T)); if(list[e.to].cost > nxCost){ pq.add(new Q(e.to, nxCost, sumT + list[now].T)); } } } myout(list[N - 1].cost); } //Method addition frame start static class Node{ ArrayList child = new ArrayList<>(); long cost = 1l << 60; int T; Node(){} } static class Edge{ int to; int C; Edge(int to, int C){ this.to = to; this.C = C; } } static class Q implements Comparable{ long cost; int nx; int sumT; Q(int nx, long cost, int sumT){ this.nx = nx; this.cost = cost; this.sumT = sumT; } public int compareTo(Q ato){ return Long.compare(this.cost, ato.cost); } } //Method addition frame end }