#include<bits/stdc++.h>
using namespace std;
using ll=long long;
using A=array<ll,3>;
constexpr ll INF=1e18;
struct edge{
    int to;
    ll cost;
};
bool chmin(ll&a,ll b){return a>b?a=b,true:false;}
vector<edge>G[105];
map<ll,ll>dist[105];
ll T[105];
int main(){
    int N,M; cin>>N>>M;
    for(int i=0;i<M;i++){
        int A,B,C; cin>>A>>B>>C;
        G[A-1].push_back({B-1,C});
        G[B-1].push_back({A-1,C});
    }
    for(int i=0;i<N;i++) cin>>T[i];
    priority_queue<A,vector<A>,greater<A>>PQ; PQ.push({0,0,0});
    dist[0][0]=0;
    while(!PQ.empty()){
        auto[c,v,p]=PQ.top();PQ.pop();
        if(v==N-1){
            cout<<c<<endl;
            return 0;
        }
        if(dist[v][p]<c) continue;
        c+=T[v];p+=T[v];
        for(edge e:G[v]){
            if(dist[e.to].count(p)==0)dist[e.to][p]=INF;
            if(chmin(dist[e.to][p],c+e.cost/p)) PQ.push({c+e.cost/p,e.to,p});
        }
    }
}