#include <bits/stdc++.h>
using namespace std;
using ll=long long;
using ull=unsigned long long;
#define rep(i,n) for(int i=0; i<(n); i++)

struct Edge{ int to; int d; };
using dijkstra_queue = priority_queue<pair<int,pair<int,int>>,vector<pair<int,pair<int,int>>>,greater<pair<int,pair<int,int>>>>;

int N,M;
vector<vector<Edge>> E;
int D[100][1001];
int C[100];

int main(){
  cin>>N>>M;
  E.resize(N);
  rep(i,M){
    int u,v,c; cin>>u>>v>>c; u--; v--;
    E[u].push_back({v,c});
    E[v].push_back({u,c}); 
  }
  rep(i,N) cin>>C[i];
  rep(i,N) rep(d,1001) D[i][d]=-1;

  dijkstra_queue Q;
  D[0][0]=0; Q.push({0,{0,0}});
  while(Q.size()){
    int p=Q.top().second.first;
    int c=Q.top().second.second;
    int t=Q.top().first;
    Q.pop();
    if(D[p][c]!=t) continue;
    c += C[p]; t += C[p];
    c = min(c,1000);
    for(Edge e:E[p]){
      int nxt = t + e.d / c;
      if(D[e.to][c] != -1 && D[e.to][c] <= nxt) continue;
      D[e.to][c] = nxt;
      Q.push({nxt,{e.to,c}});
    }
  }

  int ans=1001001001;
  rep(i,1001){
    if(D[N-1][i]!=-1) ans=min(ans,D[N-1][i]);
  }
  cout<<ans<<"\n";
  return 0;
}