from collections import *
from itertools import *
from functools import *
from heapq import *
import sys,math,time,random
input = sys.stdin.readline

INF = (1<<60)
N,M,S,G = map(int,input().split())
e = [[] for _ in range(N)]
dist = defaultdict(lambda:defaultdict(lambda:INF))
for _ in range(M):
    u,v,c = map(int,input().split())
    e[u].append((v,c))
    e[v].append((u,c))
    dist[u][v] = c
    dist[v][u] = c
def dijkstra(s,e):
    
    N = len(e)
    dist = [INF]*N
    dist[s]=0
    h = []

    heappush(h,(0,s))
    while h:
        nw,v = heappop(h)
        if dist[v]!=nw:
            continue
        for iv,ic in e[v]:
            nc = ic + nw
            if nc < dist[iv]:
                dist[iv] = nc
                heappush(h,(nc,iv))
    return dist


D = dijkstra(G,e)

X = [S]
while X[-1]!=G:
    x = X[-1]
    for i in range(N):
        if D[i]+dist[i][x] == D[x]:
            X.append(i)
            break
print(*X)