import heapq
n,m=map(int,input().split())
g=[[] for _ in range(n)]
for _ in range(m):
    a,b,c=map(int,input().split())
    g[a-1].append((b-1,c))
    g[b-1].append((a-1,c))
t=list(map(int,input().split()))
time=[float('inf')]*n
confirmed=[False]*n
q=[]
heapq.heappush(q,(0,0,0))
while q:
    now_time,now_eat,now_place=heapq.heappop(q)
    if confirmed[now_place]:
        continue
    confirmed[now_place]=True
    time[now_place]=now_time
    now_time+=t[now_place]
    now_eat+=t[now_place]
    for to_place,to_dst in g[now_place]:
        to_time=now_time+to_dst//now_eat
        if time[to_place]<=to_time:
            continue
        heapq.heappush(q,(to_time,now_eat,to_place))
print(time[-1])