from collections import deque
n,m=map(int,input().split())
ans=[[10**10]*(11**4+200) for _ in range(n)]
num=[[] for _ in range(n)]
for i in range(m):
    a,b,c=map(int,input().split())
    num[a-1].append([b-1,c])
    num[b-1].append([a-1,c])
t=list(map(int,input().split()))
ans[0][t[0]]=t[0]
queue=deque()
queue.append([0,t[0]])
while len(queue)!=0:
    num1=queue.popleft()
    h1=num1[0]
    h2=num1[1]
    num2=num[h1]
    num3=ans[h1][h2]
    for i in range(len(num2)):
        j=num2[i][0]
        if h2+t[j]<=num2[i][1]:
       	    cnt=num3+num2[i][1]//h2+t[j]
            if ans[j][h2+t[j]]>cnt:
                ans[j][h2+t[j]]=cnt
                queue.append([j,h2+t[j]])
print(min(ans[-1]))