#include <stdio.h>
#include <bits/stdc++.h>
#include <atcoder/all>
using namespace atcoder;
using mint = modint1000000007;
using namespace std;
#define rep(i,n) for (int i = 0; i < (n); ++i)
#define Inf 1000000000

int main(){
	
	int N,M;
	cin>>N>>M;
	
	vector<vector<pair<int,int>>> E(N);
	rep(i,M){
		int a,b,c;
		cin>>a>>b>>c;
		a--;b--;
		E[a].emplace_back(b,c);
		E[b].emplace_back(a,c);
	}
	
	vector<int> T(N);
	rep(i,N)cin>>T[i];
	
	vector<vector<int>> dis(N,vector<int>(1001,Inf));
	priority_queue<pair<int,pair<int,int>>,vector<pair<int,pair<int,int>>>,greater<pair<int,pair<int,int>>>> Q;
	Q.emplace(T[0],make_pair(0,T[0]));
	dis[0][T[0]] = T[0];
	
	while(Q.size()>0){
		int D = Q.top().first;
		int u = Q.top().second.first;
		int t = Q.top().second.second;
		Q.pop();
		if(dis[u][t]!=D)continue;
		
		rep(i,E[u].size()){
			int v = E[u][i].first;
			int c = E[u][i].second;
			int D2 = T[v] + c/t;
			int nt = min(1000,t + T[v]);
			
			if(dis[v][nt]>D+D2){
				dis[v][nt] = D+D2;
				Q.emplace(D+D2,make_pair(v,nt));
			}
		}
		
	}
	
	int ans = Inf;
	rep(i,1001)ans = min(ans,dis.back()[i]);
	
	cout<<ans<<endl;
	
    return 0;
}