#!/usr/bin/env python
import queue

G = [{}]

def setNode(n):
  global G
  G = [{} for i in range(n)]
def addEdge(s,t,w):
  global G
  G[s][t]=w
def getRoute(via,s,t):
    r = [t]
    y = t
    while y != s:
        y = via[y]
        r.append(y)
    r.reverse()
    return r
def solve(s,t):
  global G
  fixed = {}
  via = {}
  q = queue.PriorityQueue()
  q.put((0,s,None))
  while q.empty() == False:
    w,x,prev = q.get()
    if x in fixed: continue;
    fixed[x] = w
    via[x] = prev
    if x == t:
        return w, getRoute(via,s,t)
    for y in G[x]:
      if (y in fixed) == False:
        q.put((w + G[x][y],y,x))
  return None, None


n,m = map(int,input().split())
setNode(n)
for i in range(m):
  s,t,w = map(int,input().split())
  addEdge(s,t,w)
  addEdge(t,s,w)
src, dst = map(int,input().split())
d,r = solve(src,dst)
print(d)
print(r)