#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;
#define REP(i, n) for (int i = 0; i < (n); ++i)
#define REPR(i, n) for (int i = n - 1; i >= 0; --i)
#define FOR(i, m, n) for (int i = m; i < n; ++i)
#define FORR(i, m, n) for (int i = m; i >= n; --i)
#define ALL(v) (v).begin(),(v).end()
template<class T>bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<class T>bool chmin(T &a, const T &b) { if (b<a) { a=b; return 1; } return 0; }
const ll INF=1LL<<60;
const int inf=(1<<30)-1;
const int mod=1e9+7;
int dx[8]={1,0,-1,0,-1,-1,1,1};
int dy[8]={0,1,0,-1,-1,1,-1,1};
int main(){
    cin.tie(0);
    ios::sync_with_stdio(false);
    int n,m;cin >> n >> m;
    vector<vector<pair<int,int>>> e(n);
    vector<int> t(n);
    REP(i,m){
        int a,b,c;cin >> a >> b >> c;
        a--,b--;
        e[a].push_back({b,c});
        e[b].push_back({a,c});
    }
    REP(i,n) cin >> t[i];
    vector<vector<int>> d(n,vector<int>(1002,inf));
    d[0][0]=0;
    priority_queue<tuple<int,int,int>,vector<tuple<int,int,int>>,greater<tuple<int,int,int>>> pq;
    pq.push({0,0,0});
    while(!pq.empty()){
        auto [u,v,w]=pq.top();
        pq.pop();
        if(u>d[v][w]||v==n-1) continue;
        for(auto to:e[v]){
            int p=min(1001,w+t[v]);
            if(chmin(d[to.first][p],d[v][w]+t[v]+to.second/p)){
                pq.push({d[to.first][p],to.first,p});
            }
        }
    }
    int ans=inf;
    REP(i,1002) chmin(ans,d[n-1][i]);
    cout << ans << endl;
}