import sys

sys.setrecursionlimit(10**6)
int1 = lambda x: int(x)-1
p2D = lambda x: print(*x, sep="\n")
def II(): return int(sys.stdin.buffer.readline())
def LI(): return list(map(int, sys.stdin.buffer.readline().split()))
def LI1(): return list(map(int1, sys.stdin.buffer.readline().split()))
def LLI(rows_number): return [LI() for _ in range(rows_number)]
def LLI1(rows_number): return [LI1() for _ in range(rows_number)]
def BI(): return sys.stdin.buffer.readline().rstrip()
def SI(): return sys.stdin.buffer.readline().rstrip().decode()
# dij = [(0, 1), (-1, 0), (0, -1), (1, 0)]
dij = [(0, 1), (-1, 0), (0, -1), (1, 0), (1, 1), (1, -1), (-1, 1), (-1, -1)]
inf = 10**16
# md = 998244353
md = 10**9+7

from heapq import *

n,m=LI()
to=[[] for _ in range(n)]
for _ in range(m):
    u,v,c=LI()
    u,v=u-1,v-1
    to[u].append((v,c))
    to[v].append((u,c))
tt=LI()

mx=100000
dist=[[inf]*mx for _ in range(n)]
dist[0][0]=0
hp=[(0,0,0)]
while hp:
    d,u,p=heappop(hp)
    if u==n-1:
        print(d)
        break
    if d>dist[u][p]:continue
    p+=tt[u]
    if p>=mx:continue
    for v,c in to[u]:
        nd=d+tt[u]+c//p
        if dist[v][p]<=nd:continue
        dist[v][p]=nd
        heappush(hp,(nd,v,p))