#line 2 "/home/defineprogram/Desktop/Library/template/template.cpp"
#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define rep(i, n) for (int i = 0; i < n; i++)
#define REP(i, n) for (int i = 1; i < n; i++)
#define rev(i, n) for (int i = n - 1; i >= 0; i--)
#define REV(i, n) for (int i = n - 1; i > 0; i--)
#define all(v) v.begin(), v.end()
#define PL pair<ll, ll>
#define PI pair<int,int>
#define len(s) (int)s.size()

template <class T, class U>
inline bool chmin(T &a, U b) {
    if (a > b) {
        a = b;
        return true;
    }
    return false;
}
template <class T, class U>
inline bool chmax(T &a, U b) {
    if (a < b) {
        a = b;
        return true;
    }
    return false;
}
constexpr ll inf = 3e18;
#line 2 "main.cpp"

int N,M;
int T[105];
vector<PL>G[105];
int dis[105][1005];
int main() {
    cin.tie(0); ios::sync_with_stdio(false);
    cin>>N>>M;
    rep(i,M){
        int 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];
    rep(i,N)rep(j,1005)dis[i][j]=1e9;
    dis[0][0]=0;
    using S=pair<int,PL>;
    priority_queue<S,vector<S>,greater<>>que;
    que.push({0,{0,0}});
    while(!que.empty()){
        S p=que.top();que.pop();
        if(dis[p.second.first][p.second.second]<p.first)continue;
        for(int i=T[p.second.first];i<=T[p.second.first];i++){
            for(PL e:G[p.second.first]){
                if(chmin(dis[e.first][p.second.first+i],p.first+i+e.second/(p.second.second+i))){
                    que.push({dis[e.first][p.second.first+i],{e.first,p.second.second+i}});
                }
            }
        }
    }
    int ans=1e9;
    rep(i,1005)chmin(ans,dis[N-1][i]);
    cout<<ans<<"\n";
}