//

//  1162 I Wanna Go Home.cpp

//  Jobdu

//

//  Created by PengFei_Zheng on 20/04/2017.

//  Copyright © 2017 PengFei_Zheng. All rights reserved.

//

#include <stdio.h>

#include <iostream>

#include <algorithm>

#include <string.h>

#include <cmath>

#define MAX 0x7fffffff

using namespace std;

int n ,m;

int grah[][];

int sup[];

void dijkstra()

{

    int dis[];

    bool mark[] = {false};

    for(int i =  ; i < n; i++)

        dis[i] = grah[][i];

    int s = ;

    mark[s] = true;

    dis[s] = ;

    int newP = s;

    for(int i =  ; i <= n ; i++){

        for( int j =  ; j < n ; j++){

            if( !mark[j] && grah[newP][j] < MAX && !(sup[newP] ==  && sup[j] == )){

                if(dis[j] > dis[newP] + grah[newP][j])

                    dis[j] = dis[newP] + grah[newP][j];

            }

        }

        int min = MAX;

        for(int j =  ; j < n ; j++){

            if( !mark[j] && min > dis[j]){

                min = dis[j];

                newP = j;

            }

        }

        mark[newP] = true;

    }

    if(dis[] < MAX) printf("%d\n",dis[]);

    else  printf("-1\n");

}

int main(){

    while(scanf("%d",&n)!=EOF && n!=){

        for(int i =  ; i < n ; i++){

            for(int j =  ; j < n ; j++){

                if(i==j) {

                   grah[i][j]=;

                }

                else grah[i][j]=MAX;

            }

        }

        scanf("%d",&m);

        int x, y, len;

        while(m--){

            scanf("%d%d%d",&x,&y,&len);

            grah[x-][y-] = grah[y-][x-]=len;

        }

        for(int i =  ; i < n ; i++){

            scanf("%d",&sup[i]);

        }

        dijkstra();

    }

    return ;

}

/**************************************************************

    Problem: 1162

    User: zpfbuaa

    Language: C++

    Result: Accepted

    Time:10 ms

    Memory:2932 kb

****************************************************************/