#include<bits/stdc++.h>
using namespace std;

int INF = 1000000000;
int dist[105][1005];

int main() {
    int N,M;
    cin >> N >> M;
    vector<vector<pair<int,int>>>road(N);
    for(int i = 0; i < M; i++) {
        int A,B,C;
        cin >> A >> B >> C;
        A--;
        B--;
        road[A].push_back({B,C});
        road[B].push_back({A,C});
    }
    vector<int>T(N);
    for(int i = 0; i < N; i++) {
        cin >> T[i];
    }
    for(int i = 0; i < 105; i++) {
        for(int j = 0; j < 1005; j++) {
            dist[i][j] = INF;
        }
    }
    dist[0][0] = 0;
    priority_queue<array<int,3>,vector<array<int,3>>,greater<array<int,3>>>que;
    que.push({0,0,0});
    while (!que.empty()) {
        array<int,3> x = que.top();
        que.pop();
        if(dist[x[1]][x[2]] < x[0]) {
            continue;
        }
        x[0] += T[x[1]];
        x[2] = min(1001,x[2]+T[x[1]]);
        for(int i = 0; i < road[x[1]].size(); i++) {
            int to = road[x[1]][i].first;
            int cost = road[x[1]][i].second/x[2];
            if(dist[to][x[2]] > x[0]+cost) {
                dist[to][x[2]] = x[0]+cost;
                que.push({x[0]+cost,to,x[2]});
            }
        }
    }
    int ans = INF;
    for(int i = 0; i <= 1001; i++) {
        ans = min(ans,dist[N-1][i]);
    }
    cout << ans << endl;
}