#include <bits/stdc++.h>
template<class T> inline bool chmin(T&a, T b){if(a > b){a = b; return true;}else{return false;}}
template<class T> inline bool chmax(T&a, T b){if(a < b){a = b; return true;}else{return false;}}
#define ll long long
#define double long double
#define rep(i,n) for(int i=0;i<(n);i++)
#define REP(i,n) for(int i=1;i<=(n);i++)
#define mod (ll)(1e9+7)
#define inf (ll)(3e18+7)
#define eps (double)(1e-9)
#define pi (double) acos(-1)
#define P pair<int,int>
//#define PiP pair<int,pair<int,int>>
#define all(x) x.begin(),x.end()
#define rall(x) x.rbegin(),x.rend()
using namespace std;

using PiP = pair<ll, pair<ll, ll>>;

struct edge {
    ll to, cost;
};

int main() {
    int n, m;
    cin >> n >> m;
    vector<vector<edge>> G(n);
    vector<ll> T(n);
    rep(i, m){
        ll a, b, c;
        cin >> a >> b >> c;
        a--; b--;
        G[a].push_back({b, c});
        G[b].push_back({a, c});
    }    
    rep(i, n)cin >> T[i];
    vector<vector<ll>> d(n, vector<ll>(100010, inf));
    priority_queue<PiP, vector<PiP>, greater<PiP>> que;
    d[0][0] = 0;
    que.push({0, {0, 0}});
    while(!que.empty()){
        PiP p = que.top();
        que.pop();
        ll v = p.second.first;
        ll t = p.second.second;
        if(p.first > d[v][t])continue;
        for(auto x : G[v]){
            ll cst = d[v][t] + T[v] + (x.cost / (t + T[v]));
            if(t + T[v] >= 100010)continue;
            if(chmin(d[x.to][t + T[v]], cst)){
                que.push({cst, {x.to, t + T[v]}});
            }
        }
    }
    ll ans = inf;
    rep(i, 100010)chmin(ans, d[n-1][i]);
    cout << ans << endl;
}