import sys
import io, os
input = io.BytesIO(os.read(0,os.fstat(0).st_size)).readline

n, m, s, g = map(int, input().split())
edge = [[] for i in range(n)]
for i in range(m):
    a, b, c = map(int, input().split())
    edge[a].append((c, b))
    edge[b].append((c, a))

edge = [sorted(l, key=lambda x: x[1]) for l in edge]

import heapq
INF = 10**18
def dijkstra(s, edge):
    n = len(edge)
    dist = [INF]*n
    prev = [-1]*n
    dist[s] = 0
    edgelist = []
    heapq.heappush(edgelist,(dist[s], s))
    while edgelist:
        minedge = heapq.heappop(edgelist)
        if dist[minedge[1]] < minedge[0]:
            continue
        v = minedge[1]
        for e in edge[v]:
            if dist[e[1]] > dist[v]+e[0]:
                dist[e[1]] = dist[v]+e[0]
                prev[e[1]] = v
                heapq.heappush(edgelist,(dist[e[1]], e[1]))
    return dist, prev

d, p = dijkstra(g, edge)
v = s
ans = [s]
while v != g:
    for c, u in edge[v]:
        if d[u]+c == d[v]:
            v = u
            break
    ans.append(v)
print(*ans)