from heapq import heappush, heappop
n,m = map(int,input().split())

e = [[] for i in range(n)]
for i in range(m):
    a,b,c = map(int,input().split())
    a -= 1
    b -= 1
    e[a].append((b,c))
    e[b].append((a,c))
T = list(map(int,input().split()))

inf = 10**10
dis = [[inf]*(1002) for i in range(n)]

h = [(0,0,0)]
while h:
    d,p,now = heappop(h)
    p *= -1
    if dis[now][p] <= d:
        continue
    dis[now][p] = d
    np = min(p+T[now],1001)
    for nex,c in e[now]:

        if dis[nex][np] > dis[now][p]+T[now]+c//np:
            heappush(h, (dis[now][p]+T[now]+c//np,-np,nex))
print(min(dis[-1]))