#include <bits/stdc++.h>
//#include<boost/multiprecision/cpp_int.hpp>
//#include<boost/multiprecision/cpp_dec_float.hpp>
//#include <atcoder/all>
#define rep(i, a) for (int i = (int)0; i < (int)a; ++i)
#define rrep(i, a) for (int i = (int)a - 1; i >= 0; --i)
#define REP(i, a, b) for (int i = (int)a; i < (int)b; ++i)
#define RREP(i, a, b) for (int i = (int)a - 1; i >= b; --i)
#define repl(i, a) for (ll i = (ll)0; i < (ll)a; ++i)
#define pb push_back
#define eb emplace_back
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define popcount __builtin_popcount
#define fi first
#define se second
using ll = long long;
constexpr ll mod = 1e9 + 7;
constexpr ll mod_998244353 = 998244353;
constexpr ll INF = 1LL << 60;

// #pragma GCC target("avx2")
// #pragma GCC optimize("O3")
// #pragma GCC optimize("unroll-loops")

//using lll=boost::multiprecision::cpp_int;
//using Double=boost::multiprecision::number<boost::multiprecision::cpp_dec_float<128>>;//仮数部が1024桁
template <class T>
inline bool chmin(T &a, T b)
{
	if (a > b)
	{
		a = b;
		return true;
	}
	return false;
}
template <class T>
inline bool chmax(T &a, T b)
{
	if (a < b)
	{
		a = b;
		return true;
	}
	return false;
}

template <typename T>
T mypow(T x, T n, const T &p = -1)
{ //x^nをmodで割った余り

	if (p != -1)
	{
		x =(x%p+p)%p;
	}
	T ret = 1;
	while (n > 0)
	{
		if (n & 1)
		{
			if (p != -1)
				ret = (ret * x) % p;
			else
				ret *= x;
		}
		if (p != -1)
			x = (x * x) % p;
		else
			x *= x;
		n >>= 1;
	}
	return ret;
}

using namespace std;
//using namespace atcoder;

template<typename T>
struct edge{
  int to;
  T cost;
  edge(int a,T b):to(a),cost(b){}
};

template<typename T>
vector<T> dijkstra(vector<vector<edge<T>>> &g,int s){
  vector<T>dis(g.size(),numeric_limits<T>::max());
  using P=pair<T,int>;
  priority_queue<P,vector<P>,greater<>>pq;
  pq.emplace(0,s);
  dis[s]=0;
  while(!pq.empty()){
    auto p=pq.top();pq.pop();
    T d=p.first;
    int v=p.second;
    if(dis[v]<d)continue;
    for(auto x:g[v]){
      if(chmin(dis[x.to],dis[v]+x.cost)){
        pq.emplace(dis[x.to],x.to);
      }
    }
  }

  return dis;
}
void solve()
{	
  int n,m;
  cin>>n>>m;
  constexpr int V=2005;
  vector<vector<edge<int>>>g(n*V);
  vector<int>a(m),b(m),c(m),t(n);
  rep(i,m){
    cin>>a[i]>>b[i]>>c[i];
    a[i]--;b[i]--;
  }
  rep(i,n)cin>>t[i];
  rep(i,m){
    rep(time,V){//到着時点でしおむずびを食べていた時間
      
      if(a[i]*V+t[a[i]]+time<n*V&&b[i]*V+t[a[i]]+t[b[i]]+time<n*V&&time+t[a[i]]>0)g[a[i]*V+t[a[i]]+time].eb(b[i]*V+t[a[i]]+t[b[i]]+time,t[b[i]]+c[i]/(time+t[a[i]]));
      if(b[i]*V+t[b[i]]+time<n*V&&a[i]*V+t[b[i]]+t[a[i]]+time<n*V&&time+t[b[i]]>0)g[b[i]*V+t[b[i]]+time].eb(a[i]*V+t[b[i]]+t[a[i]]+time,t[a[i]]+c[i]/(time+t[b[i]]));
    }
  }
  auto d=dijkstra(g,t[0]);
  int ans=1e9;
  rep(i,V)chmin<int>(ans,d[(n-1)*V+i]);
  cout<<ans+t[0]<<"\n";
}

int main()
{
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	cout << fixed << setprecision(50);
	solve();
	return 0;
}