#include <bits/stdc++.h>
using namespace std;
typedef signed long long ll;

#define _P(...) (void)printf(__VA_ARGS__)
#define FOR(x,to) for(x=0;x<(to);x++)
#define FORR(x,arr) for(auto& x:arr)
#define FORR2(x,y,arr) for(auto& [x,y]:arr)
#define ALL(a) (a.begin()),(a.end())
#define ZERO(a) memset(a,0,sizeof(a))
#define MINUS(a) memset(a,0xff,sizeof(a))
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(a>b){a=b;return 1;}return 0;}
//-------------------------------------------------------

int N,M;
vector<pair<int,int>> E[101];
int T[101];
ll D[101][10101];

void solve() {
	int i,j,k,l,r,x,y; string s;
	
	cin>>N>>M;
	FOR(i,M) {
		cin>>x>>y>>r;
		E[x-1].push_back({y-1,r});
		E[y-1].push_back({x-1,r});
	}
	FOR(i,N) cin>>T[i];
	FOR(x,N) FOR(y,10001) D[x][y]=1LL<<60;
	D[0][0]=0;
	FOR(i,10000) {
		FOR(x,10) {
			FOR(j,N) if(D[j][i]<1LL<<60) {
				
				ll cur=D[j][i]+T[j];
				int sp=i+T[j];
				if(sp>10000) continue;
				FORR(e,E[j]) {
					ll t=cur+e.second/sp;
					chmin(D[e.first][sp],t);
				}
			}
		}
	}
	cout<<*min_element(&D[N-1][0],&D[N-1][10001])<<endl;
}


int main(int argc,char** argv){
	string s;int i;
	if(argc==1) ios::sync_with_stdio(false), cin.tie(0);
	FOR(i,argc-1) s+=argv[i+1],s+='\n'; FOR(i,s.size()) ungetc(s[s.size()-1-i],stdin);
	cout.tie(0); solve(); return 0;
}